Peterson last played for the Tennessee Titans for three games this season before being waived on Nov. 23. Prior to signing with the Titans, Peterson, 36, remained a free agent through the first eight weeks of the NFL season. He ran 27 times for 82 yards (3 yards per carry) and a touchdown with Tennessee as part of a committee filling in for an injured Derrick Henry.
"We're trying to get ready to win this football game," Carroll said. ... "Excited to see if he can help us out and give us a little something.
"He's a player that I've known forever, way back to his high school days and admired him tremendously over the years. Always disappointed we didn't get him back in the day (at USC). But like I just told him, we finally got him."
Where will Peterson fit in Seattle?
Seattle's lead running back Chris Carson has been sidelined with a neck injury since Week 5 and underwent season-ending surgery in November to address neck pain that's plagued him since the start of the season.
Alex Collins has carried the bulk of the running load in Carson's absence this season with 395 yards on 101 carries. Rashaad Penny returned from a calf injury in Week 7 only to see limited production before a hamstring injury sidelined him again ahead of Monday's loss to the Washington Football Team. He's not expected to be available for Sunday's game against the San Francisco 49ers.
The 3-8 Seahawks have little to play for at this point with their playoff hopes all but extinguished.