The Vikings returned to practice Sunday and were closer to full strength than they have been all summer.

Two days after playing Seattle without the left side of their offensive line and half of the secondary, the Vikings got left tackle Riley Reiff, left guard Alex Boone, cornerback Trae Waynes and strong safety Andrew Sendejo back in pads and taking part in all drills.

Ditto for receiver Laquon Treadwell, running back Latavius Murray and linebacker Kentrell Brothers, none of whom has played in the first two preseason games.

“All the guys came out for the most part and practiced good,” coach Mike Zimmer said. “It was hot out here, so it was a good steamy day. Murray got out here a little bit more, Reiff did a little more work.”

Barring injuries in practice this week, the Vikings appear ready to have all of their starters available for the first time when they face the 49ers in their third preseason game Sunday at U.S. Bank Stadium.

Quarterback Taylor Heinicke didn’t practice Sunday because of an undisclosed injury. But the Vikings still had a third quarterback after releasing linebacker Darnell Sankey to sign former Gopher Mitch Leidner.

Defensive end Brian Robison limped off the field near the end of practice because of what appeared to be a right leg injury. Zimmer said the injury wasn’t a concern.

Center battle not over

Nick Easton worked with the starting offense Sunday after playing left guard for Boone on Friday night. But that doesn’t mean his battle with rookie Pat Elflein is over.

Asked if he wants to decide on his starting five up front by Sunday’s game, Zimmer said: “We’re trying to get it done as fast as possible, but Reiff has been out and hasn’t really done much and Boone was out last week. That’s why I’m hopeful that this week we can see how it goes. We might have some different combinations in there this week, too. But I don’t know when I’ll make the decision.”

When a reporter assumed center was the only battle being waged, Zimmer left the door open for Easton and Elflein to both start.

“One of those guys might be a [starting] guard,” Zimmer said. “I don’t know. They did pretty good the other night. That factors in, too.”

That would be an unexpected twist considering right guard Joe Berger and Boone, when healthy, have pretty much locked down all the first-team reps.

As last year’s prized free-agent signing, Boone would appear to be safe as a starter. So Zimmer was asked if the team likes how Berger has been playing.

“He’s playing good,” Zimmer said. “I haven’t known him for the previous 15 years, but he’s playing well.”

‘Bulldog mentality’

There’s a reason we are all starting to notice big No. 94, Jaleel Johnson, a fourth-round draft pick out of Iowa.

“Well,” Zimmer said, “he’s playing a different spot. A spot where he can be more reckless.”

The 6-3, 316-pounder came in as a nose tackle. But he is surfacing as a playmaker at the three-technique, a spot where the Vikings need depth behind 32-year-old starter Tom Johnson.

“The other spot was almost a reading kind of technique,” Zimmer said. “This one, he can use his bulldog mentality a little bit more, I think.”

Red-zone power

The Vikings did some extra work on red-zone offense Sunday. One guy who stood out to Zimmer was Murray. Finally healthy from his offseason ankle surgery, Murray apparently is starting to show what a 230-pound back can do near the goal line.

“We had a play down there in the goal line [Sunday],” Zimmer said. “He saw the cut that he had to make and he lowered his pads and accelerated into the tackler, which I thought was good.”