Sources: Adrian Peterson to sit again

The Minnesota Vikings do not plan to play running back Adrian Peterson during Friday night's preseason game against San Diego, although the team is expecting him to argue his case for playing time in the game, league sources told ESPN NFL Insider Adam Schefter.

The Vikings still plan to have Peterson ready for their regular-season opener versus Jacksonville.

They recently increased Peterson's workload as he continues to come back from reconstructive left knee surgery.

"We're going to give him a little bit more each day, see how he responds and continue to determine what's the next step," coach Leslie Frazier told reporters Sunday. "Just go day-to-day. We have some ideas of how we want to approach it, but a lot of it depends on how he feels with some of the things we're going to give him this week."

The Vikings got mixed results on a pair of players diagnosed with concussions.

Tight end Kyle Rudolph has passed his post-concussion tests, however cornerback Chris Cook has not. Both were injured in the team's preseason game against Buffalo.

While Minnesota got one tight end back on the field in Rudolph, the Vikings won't be seeing free-agent pickup John Carlson in Friday's preseason game.

Carlson will miss the team's game against San Diego but could return for the final preseason game Aug. 30 at Houston as he continues to recover from a torn labrum in his left shoulder that sidelined him all of last season.

Information from The Associated Press was used in this report.