Just as Rashaad Penny was coming alive, his second NFL season has come to an end.
"We haven't heard back from the MRI stuff," Carroll said, "but the docs could tell he had a pretty, like I said, a significant knee injury."
Penny went down in obvious pain on the Seahawks' first drive after gaining 16 yards on a screen pass. The 2018 first-round pick had started to come on of late. After spending most of his first season and a half playing sparingly behind Chris Carson, Penny saw an uptick in his usage the previous two games, playing a combined 65 offensive snaps to Carson's 70. He delivered two of the most productive games of his career with a combined 236 yards and three touchdowns on 33 touches.
"He has had a big impact the last few weeks and we've really liked his contribution, so you miss him," Carroll said. "A guy like that, you just don't replace it. You just go to the next guy and he brings what he has. He had an explosive play when he got hurt. So unfortunately we missed him and we're going to miss him the rest of the season and I have been really excited about him turning the corner and really taking hold of this thing and contributing in a big way."
Carroll said C.J. Prosise will be Seattle's No. 2 running back behind Carson. Prosise was limited to 16 games over his first three seasons due to a string of injuries and has only played in seven games this year as a frequent healthy scratch. Rookie sixth-round pick Travis Homer is the other tailback on Seattle's roster. He recently took over kickoff return duties for Tyler Lockett and got his first career carry two weeks ago on a fake punt.
"C.J. will step into that role and Homer will help out and we'll see how those guys can do," Carroll said. "We expect them to do well. C.J.'s always done well when we've given him a chance and now he'll know he's in the game plan and all of that and I'm hoping he'll contribute in a big way."
Lockett, Seattle's No. 1 receiver, has been dealing with a shin bruise since Week 10 and more recently an illness that made its way around Seattle's locker room, but Carroll said those issues are behind him.
"He's out of that now," Carroll said. "And so it's a real positive for us. I'm glad for him."
Carroll was noncommittal about defensive ends Ziggy Ansah and Jadeveon Clowney playing this week at Carolina. Ansah (neck) was inactive Sunday night while Clowney again played through the core-muscle injury he suffered in Week 10.
"He's hurting," Carroll said of Clowney. "He's going to have to work his way through the week to make it for game day. He's playing really under the circumstances."