Mankato – And on the seventh day, Teddy Bridgewater did not rest. In fact, the Vikings rookie quarterback saw first-team reps for the first time this training camp.

As part of coach Mike Zimmer's overall plan to start sprinkling selected backups into first-team snaps for evaluation purposes, Bridgewater ran the first unit during a short series of downs during the first 11-on-11 session Wednesday.

To the untrained eye, it appeared to be Bridgewater's sloppiest practice of an otherwise steady first week of camp. To the Zimmer's trained eye, it looked … well, about the same.

"He didn't look quite as accurate as he had throughout the whole camp," Zimmer said. "But I was looking a lot at the defense today."

Matt Cassel remains the tentative No. 1 quarterback. He ran the first unit for all but the one brief series that Bridgewater got. He also got three reps with the second team.

Barr with first team

One of many reasons for Zimmer to look more at the first-team defense Wednesday was the extensive number of reps that rookie outside linebacker Anthony Barr received. It was only a matter of time before the ninth overall draft pick worked his way into a linebacker unit that sorely needs him. He's not expected to go backward on the depth chart, but that doesn't mean Zimmer is guaranteeing anything.

In fact, Zimmer probably intended to send the rookie a message via the media when asked how Barr looked.

"The only time I noticed him, he was late on a blitz," Zimmer said. "And I talked to him about it."

Blanton sits

Just when it appeared that Robert Blanton had a handle on the strong safety competition heading into the first preseason game, his hamstring became an issue when it prevented him from practicing Wednesday. He injured it during the blitz period on Monday night.

"I don't know how long [he will be out]," Zimmer said.

With Blanton down, increased opportunities went to Mistral Raymond, rookie sixth-round draft pick Antone Exum and incumbent starter Jamarca Sanford, whose own injury had caused him to fall behind Blanton earlier this offseason.

Meanwhile, Zimmer indicated that Andrew Sendejo might enter the competition Monday. That, according to Zimmer, is when the team "hopes" to have Sendejo back on the field after being sidelined because of a back injury since last season.

Munnerlyn off PUP

Captain Munnerlyn (hamstring) was taken off the physically-unable-to-perform (PUP) list and was in full pads Wednesday. But the Vikings still finished practice with punt returner Marcus Sherels in a familiar role of playing defense while those ahead of him are hurt.

Munnerlyn, the starting corner and top nickel slot guy, did some individual drills but was held out of team drills for precautionary reasons. Meanwhile, his top backup, Josh Robinson, also left the field midway through practice because of hamstring tightness.

"I don't think it will be very long for him," Zimmer said when asked how long Robinson will be out.

The plan for Munnerlyn is to get him some reps in the nickel Thursday and turn him loose full time Friday.

Searching for 'Mike'

Feeling the need to better evaluate more players he's uncertain about, Zimmer decided to discontinue Chad Greenway's middle linebacker reps in the base defense and give them to other players, particularly Jasper Brinkley and Michael Mauti.

That doesn't mean Greenway, the longtime outside linebacker, couldn't end up starting in the middle rather than the outside. He's also the likely middle linebacker in the nickel defense.

"I haven't seen enough of the other guys, is what it really is," Zimmer said. "I have to see these others. We, as coaches, have to see these other guys as far as what exactly we have at that spot. That's going to be a big contention for us.

"I told my son, Adam [linebackers coach], make sure you grade, on paper, every one of these practices. Write down the mistakes, write down the misalignments and write down the mental errors so we're on our P's and Q's with that."