ORCHARD PARK, N.Y. – The Vikings allowed their top-unit offense to play five series Friday. But that was sans two Pro Bowlers in the backfield. Fullback Jerome Felton will miss the remainder of the preseason after undergoing an emergency appendectomy on Wednesday. And coach Leslie Frazier made the decision to hold out league MVP Adrian Peterson until the team's third preseason game, Aug. 25 in San Francisco.

"Adrian's done some good things for us in practice," Frazier said. "We kind of know where he is and just didn't think it was necessary for him to play in this ballgame."

Frazier has said he wants to get Peterson at least some preseason action before turning him loose for the regular season on Sept. 8 in Detroit. So that means the reigning MVP will likely suit up next week in a national showcase game.

In Felton's place on Friday, Rhett Ellison took the first-team reps at fullback. Toby Gerhart, meanwhile, got the start at running back, gaining 23 yards on six rushes.

Fast and furious

The Vikings' defense held up well against Buffalo's fast-paced, no-huddle attack. Over the Bills' first five possessions, they netted just 69 yards and finished only one series in Vikings territory.

Linebacker Erin Henderson was encouraged by what he saw from the starters during the up-tempo session.

"I think it was good for us," Henderson said. "The league is switching up a little bit. So I think you'll see more of that. Maybe not for a whole game, but there's going to be spurts and parts of the game when teams do that. And I think we did a good job of executing and communicating and talking to one another. Which is huge for us in a situation like that on defense. Making sure you get everybody lined up is half the battle."

Bishop back in action

Desmond Bishop took the field with the Vikings' second-unit defense in the second quarter. It was the veteran linebacker's first return to game action since he tore the hamstring in his right leg on Aug. 9, 2012, during a Packers' preseason game. Bishop is fighting for a roster spot and is currently behind Marvin Mitchell at weak-side linebacker.

He sat out the preseason opener with a groin issue but said after Friday's game that everything felt good. He was credited with four tackles and combined on a sack with safety Andrew Sendejo.

Said Frazier: "You could see he was a little rusty early on. But then he settled in and began to make some plays and got comfortable communicating as well. As much as anything, it was good to see him out there running around so now he can assess where he is and so can we."

QB competition brewing

Kevin Kolb, currently the starting quarterback in Buffalo, received occasional boos during his uninspiring first-half effort. Kolb was 13-for-21 for 111 yards with an interception but also missed badly on a handful of routine throws. It remains to be seen if Kolb can hold the Bills' starting job into the regular season. Rookie E.J. Manuel, whom the team drafted 16th overall, delivered an impressive first drive to open the second half, completing all six of his passes for 44 yards on a 14-play, 80-yard Buffalo TD drive.

Flag day

After committing just one penalty in the preseason opener against Houston, the Vikings drew only three flags Friday. The first was a horse-collar penalty on cornerback A.J. Jefferson. Tyrone McKenzie was called for a hold that nullified Stephen Burton's 102-yard kickoff return touchdown.

Buffalo struggled much more in that department with 14 penalties for 106 yards.

Etc.

• Frazier said receiver Jarius Wright was the only Viking injured Friday. The coach could only say Wright was "dinged up" and was perhaps being evaluated for a shoulder issue.

• Bobby Felder broke off a 37-yard punt return in the fourth quarter and averaged 20.7 yards on his three returns.