Arizona Cardinals linebacker Deone Bucannon could miss the start of the 2017 NFL season after undergoing ankle surgery recently.

Head coach Bruce Arians told reporters Tuesday that the surgery was a result of a lingering issue and that he’s questionable for Week 1. If he has to start the season on the PUP list, then he’ll have to miss the first six games of the season.

As noted by Kent Somers of azcentral sports, this puts rookie Haason Reddick right into the starting lineup out of the gates.

Bucannon is one of the men who’s recently helped promote the use of hybrid linebackers who are essentially safeties who play in the linebacker spot. At 6-foot-1 and 220 pounds, he packs a ton of punch in a smaller package than is usually seen at the linebacker position, but he can fly.

Since being selected in the first round out of Washington State three years ago, Bucannon has started 38 games for the Cardinals. He’s been a key player on the team’s defense, racking up 284 total tackles, one interception (returned for a touchdown), five sacks and four forced fumbles.