Bears strong-side linebacker Pisa Tinoisamoa, who missed 14 games last season with knee injuries, has been ruled out of Thursday's game at Miami with a knee issue. Tinoisamoa, who has been healthy this season and consistently lauded for his performance by coach Lovie Smith, was limited in practice on Tuesday. The Bears announced today that he will not play against the Dolphins, meaning veteran Nick Roach could be in line for his first start of the season. Tinoisamoa, who is ranked sixth on the team with 41 tackles, missed the majority of the offseason program while he recovered from knee surgery. But he quickly asserted himself in training camp, as he did last summer, and claimed the starting job. The extent of his injury is not known at this point. The Bears couldn't keep their linebackers healthy last season. The team has been fortunate with injuries thus far this season. Veteran linebacker Hunter Hillenmeyer is the only player on injured reserve with any experience. Running back Harvey Unga and defensive lineman Averell Spicer are also on IR.