OTA observations: Sam Bradford held out, Terence Newman leads nickel

Starting quarterback Sam Bradford was held back Tuesday, so Case Keenum and Taylor Heinicke traded reps with the first-team offense for the Vikings.

Bradford is dealing with some "muscle tightness" and was seen throwing only during quarterback drills at the start of practice. The 29-year-old Bradford had his helmet in hand while watching the rest of practice, including all 11-on-11 sessions.

"He's got a little muscle tightness," Zimmer said. "So we just backed him off. … I think he'll be out there tomorrow."

The Vikings have two more Organized Team Activity practices this week before closing the offseason program with next week's three-day mandatory minicamp at Winter Park. The team will then break for five weeks before training camp opens in late July.

While Zimmer needed a couple weeks away to rest his surgically-repaired right eye, he kept in touch with many players and coaches as well as Bradford specifically. This is Bradford's first offseason in Minnesota since being traded to the Vikings in September.

"Sam and I have talked a lot, even when I was gone, about a lot of different things," Zimmer said. "It's been good for him to be around the players and take more of an ownership role, I guess would be the way to say it.

"He's taken on some of the things I'm trying to get him to do. I think he feels better about it."

Below are some more observations from Tuesday's OTA, the third open to reporters.

The veteran Terence Newman continued to take first-team reps as the slot cornerback with second-year Mackensie Alexander working with the second-team defense. Newman was fired up, too, jawing back at receiver Stefon Diggs after a jovial offense celebrated a deep completion from quarterback Taylor Heinicke to receiver Moritz Bohringer. Newman later deflected a Case Keenum pass while being sent on a blitz.

Linebacker Emmanuel Lamur returned, but was limited to individual work with linebackers. Edmond Robinson continued to take the first-team reps at weak-side linebacker, where the retired Chad Greenway had resided for 11 seasons. Lamur and Robinson will compete for the role in training camp this summer. Lamur is recovering from an undisclosed injury. Safety Harrison Smith has also been limited this spring after undergoing ankle surgery this offseason. Anthony Harris took his place for much of the team portion of practice.

There's a legitimate kicker competition with Marshall Koehn's leg strength standing above Kai Forbath's during three OTAs open to reporters. And at least on Tuesday, Koehn made all three of his field goal attempts while Forbath missed right on a 43-yard attempt.

Defensive end Everson Griffen is revisiting his NFL roots by shifting inside during pass-rushing situations. The Vikings have created a handful of looks along a versatile defensive line with both Brian Robison and Griffen rotating along the interior from their traditional defensive end spots. Robison has done so for a couple seasons under Zimmer, but Griffen had stayed strictly over left tackle since signing his big contract extension in 2014. Now with Danielle Hunter emerging, the Vikings are moving their ends around even more.

Quarterback Teddy Bridgewater got the "green light," Zimmer said, to progress with more exercises in his rehab during practices this week. Bridgewater spent more time Tuesday on the sideline working on his mobility and balance, including stepping through dropbacks with resistance from a band being pulled behind him by a Vikings athletic trainer.