Mike Zimmer pursed his lips and shook his head as if Aaron Rodgers had just thrown another touchdown against the Vikings.

The Vikings coach might have been replaying the lows of his eight matchups against Rodgers — six against the Vikings, two against Cincinnati while Zimmer was the Bengals’ defensive coordinator — while heaping praise on the Packers quarterback Wednesday. But history between the two has been fairly even with a 4-4 record since Rodgers became the Packers starter in 2008. In a conference call with Twin Cities media, Rodgers shared the same admiration for Zimmer ahead of their ninth meeting Sunday.

“I’ve been in the NFL 20-some years, and I can’t remember a guy that does the things that this guy does,” Zimmer said Wednesday. “Obviously, we’ve played against [Tom] Brady and … Peyton Manning, other Mannings, all these guys. This guy, when you combine everything — his arm strength, his intelligence, his escape ability, the way he sees things.”

Then Zimmer paused.

“I think they should trade him.”

The Vikings are 2-4 against the Packers since Zimmer was hired as head coach, with the franchise’s best victory of late coming in the 2015 finale for the NFC North crown. Otherwise, Rodgers largely has held the upper hand. He’s thrown 14 touchdown passes to four interceptions against Vikings/Bengals defenses called by Zimmer, whom Rodgers called one of the league’s best minds.

“He’s an innovator,” Rodgers said. “He’s brought some concepts to the league other people have tried to copy but not with anywhere near the kind of success he’s had both in Cincinnati and now in Minnesota. He’s a smart coach and has his guys well prepared. They do a good job of disguising things and making a lot of different looks the exact same and running a lot of different coverages and pressures out of it.”

Five starters held out

Quarterback Sam Bradford was kept out of Wednesday’s practice, two days after being pulled from Monday night’s 20-17 victory in Chicago. Bradford is dealing with “wear and tear” in his left knee joint, according to Vikings athletic trainer Eric Sugarman.

Four other starters also did not practice at the start of a short week. Receiver Stefon Diggs (groin), safety Andrew Sendejo (groin), defensive tackle Tom Johnson (knee) and left guard Nick Easton (calf) were also held out.

Linebacker Eric Kendricks (shoulder) and center Pat Elflein (toe) were limited during the practice.

Keenum getting comfortable

Quarterback Case Keenum has thrown four touchdown passes and has not turned over the ball, which will be a critical trend if he gets his fourth start for the Vikings on Sunday against the Packers. Keenum jumped into the middle of Monday night’s victory and led two touchdown drives against the Bears while completing 17 of 21 passes for 140 yards and a score.

“I think that says a lot about [quarterbacks coach Kevin] Stefanski and how he prepares us as a quarterback room,” Keenum said. “We see the defense through the same set of eyes. It starts with the coordinator, quarterbacks coach and then as quarterbacks being able to see everything.”

Rudolph on ‘Duck, Duck, Goose’

Tight end Kyle Rudolph said “everyone in that huddle knew what I was talking about except for” receiver Adam Thielen, the Detroit Lakes, Minn., native who knew Monday night’s group touchdown celebration only as “Duck, Duck, Gray Duck.” There was some method behind the madness.

VideoVideo (03:05): Kyle Rudolph learned a little bit about the way Minnesotans talk after the team's end-zone celebration on Monday night in Chicago.

“I don’t know where the idea came from,” Rudolph said. “I just thought, you know, no one’s done ‘Duck, Duck, Goose’ yet in the NFL. Getting the linemen involved in the celebration was something I thought would be cool. Those guys don’t usually get to celebrate a whole lot, they’re usually left out. Those guys don’t like to dance. A group dance wouldn’t have been as good.”