Packers Nation was in an uproar Monday because McCarthy opted for a pass instead of a run on first-and-goal from Buffalo's 1-yard line late in the fourth quarter. Green Bay was trailing 17-10 and had just moved the ball downfield at will with its running game.
The end result was Bills safety Ko Simpson's intercepting a tipped pass from Brett Favre, intended for Donald Driver on a quick slant, in the front of the end zone. Simpson had a 76-yard return, leading to a 14-yard, game-sealing touchdown run by Anthony Thomas.
McCarthy reiterated Monday that he went with the pass because he felt the Bills were on their heels and would be out of position with the Packers' getting up to the line quickly after a 10-yard run by Noah Herron. Instead, the offense was slow in getting the play off, enabling cornerback Nate Clements to get a jam on Driver and tip the pass to Simpson, who was playing over the top on that side.
"It was really a transition play. We were trying to get them in a personnel substitution," McCarthy said. "The mechanics of it could have been better — getting to the line quicker, catching the defense in transition.
"(But) they were not in transition when the ball was snapped, and Clements made a good play on it."
After dissecting the play several times on film, McCarthy came to the conclusion that "a run probably would have been a safer call."
"But, there's nothing wrong with the call," he contended, though allowing, "I probably won't call it again. But, it's a play I've won a game with and a play that potentially cost us the game."
Meanwhile, McCarthy had a one-word response to explain the team's other equally critical mistake in the fourth quarter: "Miscommunication."
A coverage breakdown allowed Lee Evans to get 10 yards behind cornerback Al Harris on an out-and-up route for a 43-yard touchdown that put the Bills ahead 17-10.
The secondary was in disarray before the play unfolded because strong safety Marquand Manuel had the wind knocked out of him on the previous play and had to be removed. Free safety Nick Collins already was out of the game because of a back injury, replaced by rookie Tyrone Culver. With Manuel out, cornerback Charles Woodson was moved to safety for the fateful play, with Harris and nickel back Patrick Dendy as the cornerbacks.
The initial coverage call was Cover 2, but some players said afterward that the coverage was changed to quarters, which led to confusion on the field before the ball was snapped. Harris didn't have the backside safety help he thought he would be getting in Cover 2.
"We're not all on the same page," McCarthy said. "That starts with us as coaches, and the players are accountable for what's called and carrying it out. I think once we all sit down and watch the film and see what's on the film and go through it, we'll get it ironed out."
Collins suffered a bruised lower back during the 24-10 loss at Buffalo on Sunday and was removed from the game in the third quarter. There was concern afterward that Collins might have sustained damage to his kidneys.
Collins underwent a magnetic resonance imaging test after the team returned to Green Bay, and results were negative.
"Everything looks to be fine, so I think he'll be ready to go this week," McCarthy said.
Jennings played Sunday on a badly sprained right ankle and aggravated the injury at the end of a 25-yard catch-and-run in the second quarter. He returned to the game a short time later but wasn't effective on the ankle in the second half.
McCarthy said Jennings was sore Monday.
"He'll probably miss some practice time again, and we'll know more by the end of the week. We're hopeful he'll go," said McCarthy, adding that Jennings will be listed as questionable on the first injury report Wednesday.