Vikings linebacker Anthony Barr remains sidelined because of inflammation in his surgically-repaired left knee, but Vikings coach Mike Zimmer said he expects Barr back sooner than later.

"Right now we're being careful with him," Zimmer said. Barr had season-ending surgery on that knee last November. Barr, who had taken partial part in June's mandatory minicamp, had been trying to ramp up activity during training camp, taking part in practice both Sunday and Monday. But Barr missed practice Tuesday. Then, after the team had Wednesday off, Barr was back on the sidelines Tuesday.

"Just being smart about it," Barr said. "No need to rush it right now."

Neither Zimmer nor Barr seemed overly concerned.

"I'm just frustrated," Barr said. "I wish everything was smooth. Things like this, you've got to be patient. I'm just trying to be as smart as possible. There's a long time before things get serious. I want to make sure when that time comes that I'm ready."

Zimmer wouldn't rule Barr out of Sunday's preseason opener against Pittsburgh in the Hall of Fame Game, but it would appear unlikely Barr would play. Barr has been doing some running in the pool in an attempt to keep his conditioning up.

"It's frustrating on his part and our part both," Zimmer said. "But it's legitimate. It's not like it's not a legitimate concern. [But] we anticipate he'll be back here pretty quick. … Right now we have to get the injury settled down and then start working on conditioning."

The ultimate goal, of course, is for Barr to be 100 percent for opening day.

"Our plan is to continue to get him ready and have him ready for Sept. 14," Zimmer said.

MAKING CURFEW

Center John Sullivan was back in camp after missing Tuesday for the birth of his son, John Harris Sullivan.

"I'm happy to be back," he said. "It was the best moment of my entire life. But I'm happy to be back here and putting in the work that obviously needs to be done at this time of year."

Vikings quarterback Teddy Bridgewater was asked if fatherhood had changed his center.

"I don't think so," he said. "May make him a little softer. But I don't think so."

WELCOME BACK

Zimmer was back at practice after missing Tuesday's workouts while visiting his ailing father, Bill, in Florida.

Zimmer's son Adam — the Vikings linebackers coach — and daughters Corri and Marki were all there.

At one point during the visit Zimmer pulled out his iPad and had his dad watch some film of Vikings practice. "He must have watched it for five minutes," Zimmer said.

Zimmer said his dad was doing a little better, and that he was scheduled for another procedure Thursday. Depending on how that comes out his father might be able to be moved to a longer-term facility.

READY TO GO

Vikings running back Adrian Peterson didn't have much to say about the news that he is now off probation nine months nine months after he pleaded no contest in Texas to recklessly injuring his 4-year-old son.

According to his attorney, Peterson finished one-third of his probation and its terms, allowing him to apply for early termination of his probation.

"My main thing was making sure my obligations got completed, and that's what I did," Peterson said. "The early termination is what I was aiming for, and it worked out."'

Peterson said he didn't want to do a public service announcement, and also wouldn't discuss what the obligations were. "All my obligations were worked out, and I'm off," he said.

INJURY REPORT

Not practicing Thursday were wide receiver Gavin Lutman, Barr, center Joe Berger, guard David Yankey and defensive ends Scott Crichton and B.J. Dubose. Tight end Chase Ford appeared to hurt himself making a catch early in practice and watched the remainder of the workout from the sidelines.