"It's a doctor's call on him," a serious Sherman said Friday. "We don't have to make that call until Sunday, just take every day as it is. If we think he can play and not reinjure himself, then he will play. If we think there's an outside chance that he could reinjure himself, then we'd hold him back."
Jackson, who has sidelined since the third defensive snap of the season with a dislocated kneecap, escaped knee swelling during his three days of practice. That is one reason he thinks he could play up to 30 snaps Sunday.
"I feel pretty good. We'll see how my knee reacts to (Friday's practice)," Jackson said.
Jackson's primary backup, James Lee, suffered a setback in his comeback from a knee injury when his knee swelled Thursday following practices Wednesday and Thursday. Lee sat out Friday's practice but is optimistic he will be "ready for Sunday."
"I think he'll be OK, but just thought we'd take the precaution of holding him back a little bit even though he could have used the reps, obviously," Sherman said.
The good news continued on the offensive side of the ball, with wide receiver Robert Ferguson and running back Ahman Green practicing Friday after missing the first two days of work with Achilles' tendon injuries.
Ferguson was unable to play last week against Detroit with the injury but says he feels "totally different" this week. "Last Friday I felt like I was about 20-30 percent (healthy). This Friday I feel like I'm 100 percent."
Green practiced Friday, with offensive coordinator Tom Rossley declaring the running back fit to play without limitations. If Green had been unable to practice Friday, there was a good chance he would have missed Sunday's game. His injury dates to the Family Night Scrimmage, when an ill-fitting pair of shoes led to the aggravated Achilles'.
Standout right cornerback Al Harris missed practice Friday with a nagging toe injury but should play Sunday.