He has spent most of the past month rehabbing a hamstring.
The team's first injury report doesn't come out until Wednesday, which will reveal exactly how much the fifth overall draft pick is practicing.
Coach Pete Carroll expressed doubt Friday about whether Witherspoon will be ready for the season opener Sunday.
Witherspoon was working as the nickel corner with the first team before his injury.
Seahawks General Manager John Schneider said before Monday's practice that Witherspoon was doing “really good’’ before he was sidelined.
“He was taking reps inside, and I think we talked about it around the draft, his route anticipation and awareness and feel for crossers and people behind him is really impressive,’’ Schneider said, via Bob Condotta of the Seattle Times.
Coby Bryant has been working as the primary nickel back in place of Witherspoon.