Antoine Bethea placed on season-ending injured reserve by 49ers

The San Francisco 49ers placed strong safety Antoine Bethea on season-ending injured reserve Friday after last season's team MVP suffered a shoulder/chest injury in a 20-3 loss to the Seattle Seahawks.

The cleared roster space allowed the Niners to activate receiver Jerome Simpson from the reserve/suspended list. He was serving an NFL-mandated six-game suspension to begin the season. With a short week, the Niners received a roster exemption for Simpson before the Seahawks game.

Bethea, 31, appeared to injure himself in the second quarter Thursday night when he was flagged for a facemask penalty on Doug Baldwin. The force of Bethea yanking on Baldwin's helmet apparently caused the injury. He was scheduled to undergo an MRI exam on the injury earlier Friday.

Bethea started each of his first 23 games after signing with the Niners as a free agent last year following eight seasons with the Indianapolis Colts.Last season, Bethea tied a career high with four interceptions, including his first career touchdown, and had a career-best 10 passes defensed with 72 tackles, a sack and a forced fumble.

This season Bethea had 32 tackles and a sack.

He should be replaced by rookie Jaquiski Tartt, the Niners' second-round draft pick from Samford, who suffered a leg contusion Thursday night and has 21 tackles and a sack thus far.