Saquon Barkley is one of the top players to watch at the 2018 NFL Scouting Combine

College football teams often navigate non-conference action without terrific performances from their stars, but the best players must start to take over in conference games.

Not every team is preparing for a league contest, but the Week 4 slate is loaded with opportunities for key contributors to stand out. We’ve identified a group of players who will have the greatest impact on the outcomes.

James Blackman, quarterback, Florida State

When Florida State returns to the field for the first time since losing to Alabama, there will be a new face under center. James Blackman, a true freshman, will be called upon to replace Deondre Francois. How will the first-time starter perform? Your guess is as good as mine, since the 6-foot-5, 169-pounder will be tested immediately. North Carolina State has encountered some struggles in coverage, but the defensive line is stout against the run. Given the likelihood FSU’s blocking unit struggles to create lanes, Blackman might already be tasked with winning a game through the air.

Kyle Allen, quarterback, Houston

Houston has a respectable defense, but Texas Tech quarterback Nic Shimonek will spread and stretch the secondary as far as possible. The signal-caller with 927 yards and nine touchdowns will be tough to stop. So, Houston might need to keep up, and that responsibility falls on Kyle Allen.

The Texas A&M transfer wasn’t great in his team debut, but that changed during a blowout of Rice. Allen completed 31-of-33 attempts for 309 yards and two touchdowns. Although Texas Tech’s defense probably won’t actually do much defending, matching Shimonek’s pace is no easy task.

TaQuon Marshall, quarterback, Georgia Tech

Georgia Tech quarterback TaQuon Marshall

Pitt has been allergic to defense through three games, but the embarrassment against Oklahoma State, return of safety Jordan Whitehead and start of conference play could refocus the Panthers for a week. Georgia Tech, which has hopes of a Coastal Division crown, cannot let that matter.

TaQuon Marshall exploded for 249 rushing yards and five touchdowns when the Yellow Jackets loss to Tennessee, and he tossed three scores during a victory over Jacksonville State. Marshall will lead the superior attack, but a fumbled exchange or misplaced pitch could stop Georgia Tech from recording an important ACC win.

Ty Johnson, running back, Maryland

Perhaps the most quietly explosive player in the country, Ty Johnson has racked up 256 yards and three touchdowns on just 17 carries this season. Central Florida, which hasn’t played since August 31 due to Hurricane Irma-related cancellations, might be shaking off some rust in the early moments, and any lapse will create a breakaway chance for Johnson. UCF’s offense is capable of sticking with the Terps, so Johnson — who may also return kickoffs — must take advantage of any mistakes to push Maryland ahead early.

Calvin Ridley, wide receiver, Alabama

To this point, Alabama hasn’t been required to throw many passes. But Vanderbilt and its No. 28 rush defense might complicate the game plan for the Crimson Tide, who have a primary target in Calvin Ridley and some questions behind him. The junior leads Alabama with 15 receptions, 219 yards and two touchdowns. The next-highest marks are 6-75-1, respectively. Part of low production is that the Tide haven’t forced the aerial attack, but Ridley has accounted for 34.8 percent of the team’s targets. Alabama could use a more diverse passing game, but until that happens, Ridley needs to stay productive as the key wideout.

Mason Rudolph, quarterback, Oklahoma State

Oklahoma State’s offense hasn’t disappointed, carrying the Pokes to 3-0 behind 600-plus yards and 54 points per game. Mason Rudolph has posted a 72.3 completion percentage with 1,135 yards and 13 total touchdowns. Though the competition hasn’t been great, Rudolph and Co. haven’t left any doubt about the better team. TCU wants to change that. The Horned Frogs played an excellent game at Arkansas but struggled defensively against SMU. While his scorching pace is unsustainable, Rudolph must avoid a letdown to help Oklahoma State begin Big 12 action with a victory.

Logan Woodside, quarterback, Toledo

Logan Woodside led the Football Bowl Subdivision with 45 touchdown passes in 2016. He just tossed six during a shootout win over Tulsa. Can the senior continue the hot streak against Miami? Mark Richt’s squad hasn’t played since Week 1, and the secondary isn’t exactly a lockdown unit.

If the Toledo offensive line can handle the front seven — though that is no guarantee — Woodside could give the Hurricanes a real fight for 60 minutes. Miami turned the “Appalachian State upset special” of 2016 into a complete laugher, so it’s wise to not get carried away. That doesn’t change Woodside being a dangerous passer.

Jalin Moore, running back, Appalachian State

The departure of Marcus Cox seemed to offer Jalin Moore a clear path to stardom. Three weeks into the 2017 campaign, he’s still looking for the quickest path. Moore, who registered 1,402 yards and 10 touchdowns as the Sun Belt’s Offensive Player of the Year last season, has mustered 109 yards and one score on 31 carries.

What better time to turn around a slow start then against Wake Forest? However, the Demon Deacons have ceded just 3.3 yards per attempt in three wins. Appalachian State has dreams of an upset, but that’ll only happen if Moore puts together his first big day.

Daniel Jones, quarterback, Duke

Duke managed just four wins last season. But with a victory over rival North Carolina in Week 4, the Blue Devils will have already matched that mark. Sophomore quarterback Daniel Jones deserves a fair share of the credit for the turnaround, especially since the offensive line has surrendered six sacks and 10 hurries over the last two games.

North Carolina has 23 combined sacks and hurries this season, so Jones may be under considerable pressure Saturday afternoon. How he responds will determine whether Duke kicks off its ACC schedule with a win.

Wilton Speight, quarterback, Michigan

Calling a stat unsustainable isn’t always meant to temper expectations about a positive output. Michigan has only scored one touchdown in 10 trips to the red zone. Still, we can’t be certain when the trend will regress toward the mean. Wilton Speight is an ugly 1-of-13 for negative-one yard inside the 20-yard line.

Purdue, meanwhile, has forced four field goals and recovered two fumbles on defense in red-zone situations. The Jeff Brohm era is off to a promising start, and the Boilermakers would love to conclude its September slate with an upset over Michigan. But if Speight and Co. consistently finish drives, that dream won’t have a chance of coming true.

Nick Chubb, running back, Georgia

Caption: Dec 30, 2016; Memphis, TN, USA; Georgia Bulldogs running back Nick Chubb (27) before the game against the TCU Horned Frogs at Liberty Bowl. Mandatory Credit: Justin Ford-USA TODAY Sports

In the battle of the Bulldogs, Georgia is the favorite. We don’t need any more evidence than a 37-7 dismantling of LSU to prove Mississippi State is a legitimate threat, though. While dual-threat quarterback Nick Fitzgerald has grabbed much of the attention, Mississippi State’s run defense has allowed just 2.6 yards per carry this season.

For better or worse, Georgia will challenge that strength. Plus, since Nick Chubb has only logged 44 attempts so far, the powerful back should be rested and ready for a 25-to-30 touch game. And Georgia might demand it from him.

Arion Worthman, quarterback, Air Force

San Diego State vaulted itself into the national discussion thanks to an upset of Stanford. Arion Worthman and Air Force would enjoy promptly removing the Aztecs from that perch. Additionally, the Falcons will be looking to rebound because — even in a competitive loss to Michigan — it was the program’s worst showing on offense in a half-decade. But excluding the game nobody expected Air Force to win, Worthman is undefeated as a starter. He’s absolutely capable of exploiting San Diego State if the defense has a Stanford hangover.

Saquon Barkley, running back, Penn State

Through three weeks, Saquon Barkley has gathered 307 rushing yards, 11 receptions for 241 yards and five total touchdowns. The Heisman Trophy-worthy start simply hasn’t been discussed much because Penn State waltzed past Akron, Pitt and Georgia State.

However, his competition level is about to rise. The Nittany Lions have a potentially troublesome Big Ten opener at Iowa. We don’t really know which Hawkeyes offense will show up, but Barkley can shape the outcome if he gashes Iowa — again. He amassed 211 all-purpose yards and two scores in a 41-14 win last year.

Garrett Johnson, wide receiver, Kentucky

With a nod to running back Sihiem King, Garrett Johnson will play an integral role Saturday night when Kentucky tries to snap a 30-game losing streak to Florida. Once spurned by the school, Johnson has one final opportunity to beat the program that didn’t offer him a scholarship. Off-field dramatics aside, he’s the No. 1 receiver for the Wildcats, and Florida has an excellent secondary. The unit has intercepted five passes and returned three for touchdowns in just two games. Despite that tight coverage, Johnson must be a reliable target in crucial moments for Kentucky.

Brian Lewerke, quarterback, Michigan State

Michigan State knocked off Notre Dame last season because of a balanced rushing attack and solid defense, but Tyler O’Connor had a knack for converting third downs in the matchup. The torch has been passed to Brian Lewerke, who is an upgrade both as a runner and passer. In two victories this season, he’s posted 561 yards of total offense and accounted for six touchdowns while helping MSU move the chains 15 times in 30 third-down situations. That balance and timely success will be critical in the Spartans’ efforts to derail Notre Dame.

Steven Montez, quarterback, Colorado

Colorado’s defense is plenty talented, but mistakes on offense can be the team’s undoing. During the 2016 Pac-12 Championship Game, the Buffs only trailed Washinton 14-7 at halftime. Then, three interceptions after the break — including a pick-six on the opening play of the third quarter — led to 13 points for the Dawgs. Steven Montez didn’t throw any of the interceptions, yet he fully understands the challenge of playing UW after going 5-of-12 for 60 yards in temporary relief of Sefo Liufau. Montez, who just recorded career-best outputs of 357 yards and four touchdowns in a win over Northern Colorado, needs to play a mistake-free game for Colorado to stun Washington.

Josh Rosen, quarterback, UCLA

What else can UCLA expect from the junior? He’s already piled up 1,283 yards and 13 touchdowns, led a 34-point comeback and propelled the Bruins to 45-plus points in every game. But the bad Josh Rosen keeps flaring up. The most obvious poor decisions have been launching several off-balance downfield prayers and the game-defining pick-six at Memphis where he threw late and across the middle. Rosen certainly isn’t receiving help from his defense, but this is his reality. Those mistakes cannot be repeated when UCLA faces an unforgiving opponent in Stanford.