There are three games remaining in the 2017 season and the 6-7 Cardinals are a long shot to reach the playoffs.
If Peterson is unable to suit up against the Washington Redskins on Sunday, Williams will likely continue to hold down the primary duties in the running game. Arians was unspecific about the issue last week, noting there was no timeline for a return. "It's a matter of taking a hit, and getting all his strength back".
Unfortunately, injuries have been an issue for Peterson throughout his career and especially lately.
He missed 11 games last season with a torn meniscus and also sat out games in 2013, 2011, 2010 and 2007 with injuries.
Considering his age and injury history, another extended absence could create even more question marks about his future. The Cardinals are out of it, and there's a real chance we saw the last of Peterson playing in the National Football League if he doesn't suit up the rest of this season.