Adrian Peterson will carry the ball sometime during the preseason, but Vikings coach Leslie Frazier was still vague about when that might happen -- although Frazier at least narrowed it down to either Friday's game at Buffalo or the third preseason game at San Francisco.

"Between this week and next week would be the time we're going to play him, if we play him in the preseason," Frazier said Wednesday after the Vikings' final walk-through in the Mankato portion of training camp. "We want to do something in these next couple of weeks."

Obviously Peterson, and most of the team's key players, will sit out the fourth preseason game Aug. 29 against Tennessee at the Metrodome. The regular season opens Sept. 8 at Detroit.

A larger-than-average morning crowd was present Wednesday for Fan Appreciation Day at Mankato. The team has its final padded practice in Mankato this afternoon. The players will spend their final night in the dorms before traveling back to the Cities and flying to Buffalo tomorrow.  The team resumes training camp at its Winter Park facility on Sunday.

One thing is known: Quarterback Christian Ponder will get a lot more action against the Bills than he did in last Friday's preseason loss to Houston at the Metrodome, when he threw only two passes.

"Hopefully I can more than quadruple that number," he joked. "Hopefully play a lot more ... I guess the plan is at least a quarter."

Frazier was effusive in his praise of the Minnesota State University training site, and said the three-week portion of camp has been "very successful."

"We were able to cover a lot of ground, and introduce our players to how we want to do things over the course of the season," he said.

After missing last week's game because of a hamstring injury, rookie first-round pick Xavier Rhodes will get a long look against Buffalo.

"We want him to get a feel for the speed of an NFL game," said Frazier.  Josh Robinson and Chris Cook will be the starting corners, with Rhodes getting a lot of action as the nickel back.

Frazier hoped for a quiet final night in Mankato.

"I hope none of our players has big plans," he joked.