This was supposed to be D'Qwell Jackson's comeback season. It's over already.

In a somewhat surprising move, the Browns placed the linebacker on injured reserve Saturday because of a right chest muscle injury — the same kind that ended Jackson's 2009 season with 10 games left.

Jackson, who led the NFL in tackles in 2008, had just returned to practice this week from a partially torn chest muscle sustained in training camp on Aug. 10. He practiced Wednesday and felt fine, but after practice on Thursday, he felt tightness and fatigue in his pectoral muscle.

On Friday, Jackson, who had hoped to play Sunday in Baltimore, said he and the team's training staff were being cautious and shutting him down. He expected to practice again next week and was sure he would be able to play again this season.

But the Browns decided to put him on IR for the second straight year, a blow to one of their steadiest players who turns 27 on Sunday. Jackson is in the final year of his contract and he had been hoping to work out a long-term deal with Cleveland, or impress other teams to sign him as a free agent.

Now, after two major injuries in two years, his career is in jeopardy.

Jackson missed Cleveland's final 10 games in 2009 after tearing his left pectoral muscle and needing surgery.

The Browns replaced Jackson on their roster with Sam Aiken, a veteran wide receiver released by New England earlier this month.

Aiken may need to get ready quickly for the Ravens after the Browns announced that wide receiver Brian Robiskie will miss Sunday's game with a hamstring injury and that receiver/kick returner Joshua Cribbs is questionable with an ankle injury.

Robiskie pulled up during practice on Thursday and Cribbs got hurt on Friday.

The Browns also said nose tackle Shaun Rogers will sit out with a leg injury.