Garrett Bradbury at center, Pat Elflein at guard for Vikings; Stefon Diggs skips OTA

In front of Kirk Cousins were center Garrett Bradbury and left guard Pat Elflein. That's how the Vikings offensive line took shape Wednesday during the second organized team activity (OTA) practice, the first open to reporters.

Elflein, entering his third NFL season, is making the transition back to guard after 30 games as the Vikings center. He played guard at Ohio State and a healthy offseason has given him more confidence about his return to that position.

"I was in the weight room," Elflein said. "I wasn't in the hospital this offseason."

Lingering recoveries from shoulder and ankle surgeries stunted Elflein's 2018 season, a year after he was a promising third-round rookie. Rehabilitation prevented progress in the weight room, where his goal since is to "add as much muscle" as he can.

While Bradbury works at center and learns protection calls, Elflein's focus has narrowed.

"That's not my responsibility anymore," Elflein said. "At the line of scrimmage, I can focus on other things."

Bradbury, drafted 18th overall, is the literal and figurative center of the Vikings' overhauled interior offensive line, also featuring right guard Josh Kline, a free agent signing. Building a rapport with Cousins is critical for Bradbury after the Vikings quarterback had four different centers last year from training camp through September.

Right tackle Brian O'Neill was sidelined at practice for an undisclosed reason. Rashod Hill anchored the right side, followed by Kline, Bradbury, Elflein and left tackle Riley Reiff.

The only Vikings player missing from Wednesday's voluntary practice was receiver Stefon Diggs, who has not attended either of two OTAs held this week.

Diggs, 25, has been present sparingly throughout the Vikings' offseason program that began April 15. He's expected to return Thursday, according to Cousins. Coach Mike Zimmer said Diggs' absences did not concern him. Diggs would be at risk of losing a $100,000 workout bonus if he missed more than 10% of the offseason program without consent.

"That will be fun to have him back," Cousins said.

Nose tackle Linval Joseph is being held out of full-team drills (offense vs. defense) while recovering from offseason surgery, according to Zimmer. Joseph ran through warmups and defensive line drills and said he feels "great."

"I can't wait to get back," Joseph said. "Right now, I'm just trying to help the team anyway I can."

Defensive end Tashawn Bower is being held out while recovering from ankle surgery.

Cornerback Xavier Rhodes was the subject of criticism this offseason from Zimmer, who said Rhodes needs to play up to his contract in 2019. Rhodes, a 2017 first-team All-Pro selection, said he talked things over with Zimmer and they came away with an agreement about where the seventh-year cornerback can improve.

"It was some situations where I thought I knew the play, gambled on plays, doing things out of character," Rhodes said, adding injuries were still a key factor in his down season. "No player is going to be out there with multiple injuries and play to their potential."

• Cornerback Mike Hughes, with a brace on his left knee, continued rehab from October surgery off to the side of practice.

• As the Vikings try to replace returner Marcus Sherels, receivers Chad Beebe, Davion Davis and Jordan Taylor were among Wednesday's candidates fielding punts.

• Tight end David Morgan (undisclosed reason) was held out of practice.