Vikings running back Adrian Peterson made another step in his recovery from knee surgery Monday at Winter Park when he was allowed to take contact.

Not full contact, not yet. Vikings defenders were given the green light to hit Peterson above the waist, but they weren't allowed to drive him into the ground. Now coach Leslie Frazier and the Vikings coaching and medical staffs will see how Peterson's left knee responds.

"Today is another step in the process," Frazier said.

Know this: Peterson was excited about the decision.

"He told [running backs coach] James Saxon, he said, 'Coach, you better tell those defenders to buckle up,' " Frazier said. "I knew it would get him fired up. He did pretty good. We'll see how he feels."

It is a significant step in a process that has had Peterson ahead of the rehab curve all the way through. He was allowed to return to practice two weeks ago. Last week, the Vikings decided Peterson would not take part in a preseason game, and he appeared to accept the decision. Now the question is whether Peterson will be good to go for the Sept. 9 regular-season opener against Jacksonville, which has been the goal all along.

"I want to see what he has to say after today," Frazier said. "Then we need to go through a whole week with him in the game plan to see how he responds."

Schwartz returns A day after tight end John Carlson returned to practice, the Vikings got another addition when guard Geoff Schwartz donned pads and a helmet and took the field to practice for the first time since he had hernia surgery Aug. 7.

Schwartz was expected to compete with Brandon Fusco for the right guard spot before being injured. He was not cleared for full practice Monday, taking part in offensive line drills only. But it was a significant step for Schwartz, who was not slated to return to practice until next week. It is unclear whether he'll be available for the opener.

"He should have a good, full week to work with our team," Frazier said. "So we'll see how it goes.

Accentuating the positive Vikings offensive coordinator Bill Musgrave admitted Monday his offense wasn't firing on all cylinders in Friday's 12-10 preseason loss to San Diego. But he was inclined to look at the bright side.

"We did some things better than we ever have done them before," he said.

What things? Musgrave was talking about the emphasis he is putting on getting big plays through the air.

"We hit Percy [Harvin] on a 40-yarder and missed a 54-yarder [to Harvin]," Musgrave said. "We're doing a better job of achieving those chunks down the field. We did that against Buffalo [Aug. 17] as well. We want to be able to do that, which will complement our strong running game."

Against Buffalo, Vikings QBs completed four passes of 21 or more yards, with Christian Ponder having three of those.

Etc. • Defensive backs Chris Carr (back), Marcus Sherels (ankle), Andrew Sendejo (ankle) and Mistral Raymond (back), and fullback Ryan D'Imperio (shoulder) missed a second consecutive day of practice.

• Frazier said cornerback Reggie Jones could get some work returning punts in Thursday's preseason finale at Houston. Backup running back Jordan Todman might return kickoffs.

• While most of the Vikings' starters will not play in Houston, Frazier said there is a chance a couple could, naming Fusco and rookie safety Harrison Smith as two who could see the field.