The Miami Dolphins will be without prized second-round pick, linebacker Raekwon McMillan, the rest of the season.

An MRI confirmed what the Dolphins feared might be the case after McMillan suffered a knee injury Thursday night — an ACL tear that will require surgery.

A rookie out of Ohio State, McMillan had been impressing coaches this offseason and during training camp. He was already playing with the starters, though there was still some competition between him and veteran Lawrence Timmons for a starting job at inside linebacker.

This injury is a huge setback to the rookie, and to the Dolphins as a whole. Unlike their quarterback situation, which was resolved very smoothly, McMillan’s absence from the lineup won’t be easily filled.