Tinoisamoa had his right knee scoped on Dec. 3, and he has been excluded from drills at practice.
"We feel like we have a lot of games left," Tinoisamoa said. "My goal is to get healthy, so when the games do count in the postseason, I'll be able to contribute good stuff.
"It was painful. I'd go home, and it would hurt. Walk around, and it would hurt. I mean, that's not right. It's not supposed to do that. Now I got some relief, it doesn't hurt anymore. That's good."
Meanwhile, strongside linebacker Nick Roach's chances of playing Sunday look promising.
Roach hit the practice field for the second straight day on Friday and participated on kickoff return in the special-teams portion of practice, then worked with the first team in a defensive back seven drill. The linebacker hurt a muscle in his lower back/hip region in the Bears' 24-20 win over the Detroit Lions, but appears to be recovering in time to start for the third time in four weeks.
"It's good to get [Roach] back out there, Nick is a good football player," Bears head coach Lovie Smith said. "With Pisa down, we could use Nick Roach. We didn't think it was anything serious with him, [and] he got better as the week went along. He was able to practice today, hopefully he'll be able to go Sunday."
The Bears officially list Roach as questionable.
Defensive tackle Marcus Harrison returned to practice after being forced to miss Thursday due to an illness.
Jeff Dickerson covers the Bears for ESPNChicago.com.