Vikings linebacker Chad Greenway said he has missed three tackles in the first two games and has not performed "up to my ability," but he said surgery on his left knee in June is not a lingering problem.

"No effect," he said.

Coach Leslie Frazier indicated that Greenway's slow start might be the result of his forcing the issue with two new starters in the linebacker corps.

"He does not have to make anybody else's plays," Frazier said. "Just do your job, calm down, relax and play the way he's always played. Just don't feel like you have to do any more other than your job."

Frazier acknowledged that it's possible Greenway is trying to provide help to new middle linebacker Erin Henderson.

"There's a tendency for that to potentially happen with a new guy across from you," Frazier said. "You've just got to trust that he's going to do his job, you do your job and we'll be fine as a group."

Greenway told reporters that it's impossible for outside observers to know exactly how any player is performing because they don't know a team's scheme or individual responsibilities.

"A lot of times it's easy to pick apart what's out in the open and can be seen, that everybody can see," he said. "But it's the things that happen that people don't understand that can't be graded or can't say, 'Hey, he's doing good' or 'He's doing bad.' The reality is you guys don't have any idea what's really being taught or what's being coached in that room."

Patterson's patience

A day after Frazier called Cordarrelle Patterson's lack of playing time a "major oversight" by the coaching staff, the rookie wide receiver downplayed the situation. Patterson has played only 11 offensive snaps total in the first two games.

"It doesn't matter how many plays you play; it's what you do with the plays you get," Patterson said. "Maybe I get more plays and I make more mistakes. It really doesn't matter about the reps. I make the best out of the little ones I get."

The Vikings have used Patterson primarily on bubble screens in his limited chances. He has been targeted three times and has three catches for 24 yards. Patterson said his size (6-2, 220 pounds) and patience make him effective on screens.

"Some guys, they're impatient," he said. "They get the ball and go with it. I rely on my offensive linemen and my blockers to help me out."

Bishop's role to increase

Veteran linebacker Desmond Bishop was active but did not play in the season opener at Detroit. He played two snaps against the Bears, which was partly the result of the Vikings being in their nickel defense so often, Frazier said.

Marvin Mitchell, the third linebacker in base defense, played only 25 of 67 plays on Sunday. Regardless, Frazier said he expects Bishop's playing time to increase starting this week.

"We want to get him a few more snaps, some more time on the field and see what he does with that," Frazier said. "He seems to be much more comfortable in our defense now than a few weeks ago."