I don't see why he would be inactive. Starting and/or playing much is a different issue. If he is to be used in the playoffs, now is the time to figure out if his fumbling issue can be fixed or not. Running the fumbling percentages is nice, but with his sloppy technique his numbers could be significantly higher. I don't find much comfort from a statistical rate as his failures are evident to fans so will be a clear target for other teams.
As for Faulk, I believe BB realized he was used improperly at a time when the Pats had few RB options (the expiring Terry Allen was option 1 his rookie year and he was largely doing kickoff returns, then Faulk was the primary back when he had career highs in carries and fumbles, then Antowain Smith took over as lead RB (as Smith lagged in 2003, Faulk's carries went up but Dillon was brought in)). In his
retirement news conference, BB stated "I’d say in my coaching career, nobody has ever worked harder to do the things that he was asked to do, from that season on – in terms of ball security, blitz pickup, having different roles in the game and that changes from week to week." Faulk sat down with BB in early 2000, the beginning of his second year, and discussed what he needed to do to stay as a Patriot.
Faulk stuck around because he was diverse (KR, RB, receiving, blocking) and a hard worker. He worked hard to fix his weaknesses and develop a broad skill set. Ridley is a one-trick pony, so it would appear wise to focus on weakness in that one area. I didn't find it comforting that Ridley in year 3 after 4 fumbles by game 11 declared he wanted to discuss fumbling problems with Faulk. That feels a little late to the party if he has a work ethic and not just talent. I hope he fixes the issue, because he can be huge for the team if he does. He won't do that from the sidelines.