It had been 25 days since John Carlson last practiced. So when the Vikings tight end was given the green light to get back in the mix Sunday, he did so with predictable eagerness. Carlson knows he has a lot of missed time to make up for. But he also doesn't want to push things too fast.

After all, the medial collateral ligament he sprained in his right knee in the second padded practice of training camp needed time to strengthen.

And above all else, Carlson had to remind himself that his return to action must come with some caution.

"The MCL creates stability issues," he said. "So lateral movement for me is still a work in progress."

Coach Leslie Frazier said Carlson "moved around pretty good" during Sunday's light practice, an encouraging step for a free agent acquisition whom the Vikings expect to consistently deliver in 2012.

The Vikings will not use Carlson in their preseason finale Thursday in Houston, planning to hold out just about every player who has a chance of starting. But the expectation is that Carlson will be ready for the season opener Sept. 9 against Jacksonville.

Still, the veteran tight end stopped short of saying he would be 100 percent for that game.

"The funny thing about football is that no one is at 100 percent strength, even for the season opener," Carlson said. "Anyone who's been in training camp and anyone who's missed training camp because they're hurt, they're not at full strength. That's just the nature of football. So I'll do my best to get myself in the best shape possible in the next two weeks and we'll see where that leads us."

After a shaky offensive outing in Friday's 12-10 home loss to the San Diego Chargers, Frazier's review of the film uncovered deficiencies "across the board." The offensive line seemed to take a small step backward. Quarterback Christian Ponder wasn't sharp with his pocket presence. The wide receivers didn't make many plays. And as a whole, the offense never found much of a rhythm.

It was a reminder that, even with all the progress that seemed to come during training camp, the Vikings offense is still a long way from being a polished product.

Carlson's return should help, allowing offensive coordinator Bill Musgrave to uncork his tight end-friendly play calling more often. Carlson and Kyle Rudolph both have grand visions for what's ahead and have enjoyed working in tandem throughout the offseason.

"John's been in the league four years," Rudolph said. "He's been around the block. And even while he was hurt on not on the field, he was recognizing things and helping us with technique and other little things that some of us younger guys are still learning.

"Now, getting him back on the field, to have the luxury of us putting two tight ends on the field will be huge. Defenses will have to go with their base personnel and they'll have a hard time matching up."

Carlson said he believes improving his conditioning will be the biggest challenge over the next two weeks, also noting that all that missed practice has left him somewhat rusty with his releases on pass routes and his footwork while blocking.

"I've missed an awful lot of physical reps," he said. "So I'm trying to get as many reps as I can in the next two weeks to get that feel back."