Rodgers left Sunday’s game at Detroit in the second quarter with a concussion, his second in a span of nine games. On a scramble, his head slammed to the turf as a result of a hit by linebacker Landon Johnson, and after a few more snaps, the medical staff determined he shouldn’t continue playing.

“When it became a question, an issue, was he clear, wasn’t he clear, we pulled him immediately,” McCarthy said. “We’ll always take the high side of caution in these types of situations.”

Following his previous concussion, which occurred on the offense’s last play of the game at Washington in Week 5, Rodgers passed the post-concussion testing the following week and practiced on a limited basis on Thursday and Friday prior to the Sunday game vs. Miami.

There’s no telling at this point whether the latest concussion is any more or less severe than the first one, but that’s in part why the testing protocol is in place. Each player has a cognitive test on file that serves as his baseline, and after a head injury, test results must return to that baseline level before the player is eligible to return to practice. The player also must be cleared by an independent neurologist.

McCarthy said after Sunday’s 7-3 loss that Rodgers’ head was clear but he had a headache. He was allowed to sleep in on Monday morning before returning to the team facility to meet with the medical staff and take the first steps in the post-concussion testing process.

If Rodgers is unable to play this week at New England, backup Matt Flynn would get his first NFL start and the team would need to add a quarterback to the roster as his backup. Practice-squad quarterback Graham Harrell would be one option, McCarthy said.

In the most extensive action of his three-year career, Flynn performed admirably but inconsistently. In six possessions, he put together drives of 43, 81 and 60 yards but produced just three points, mostly due to an interception in the red zone to conclude the 81-yarder.

McCarthy also pointed to a couple of missed throws as a key downfall, none bigger than his last two on the final drive – a ball that slipped out of his hand on a crossing route to an open Donald Driver on third-and-1, and an overthrown fourth-and-1 shot to the end zone to Greg Jennings, who had a step on the defender.

“He was productive as far as moving the offense,” McCarthy said. “We didn’t help him as far as the run game. The protection was not a positive. But he had an opportunity to make some throws, and he made some throws and he missed some throws.”

Flynn did hit Jennings for a 32-yard gain down the sideline, the longest pass of his career, during a stretch of three straight completions in the third quarter. He also completed five straight passes on the final drive before the two missed throws ended the Packers’ comeback chances.

Those two plays came right after Brandon Jackson was stopped a yard short of the first down on a second-and-2 draw play. Offensive coordinator Joe Philbin lamented all three plays in that sequence as opportunities missed.

“The thing we stressed to our guys is we had a second-and-2, a third-and-1 and a fourth-and-1 with the game on the line,” Philbin said. “As poorly as we had played and as frustrated as probably we all were offensively, we had a chance to win the game. We had to make one of those plays to extend the drive to keep playing and keep things alive, and unfortunately we didn’t come up with the play.”

A couple of mental errors also were unfortunate, and costly. Flynn stepped the wrong way at the snap on a third-and-1 running play and never got the handoff to John Kuhn, resulting in a 4-yard loss and a punt, which preceded Detroit’s game-winning scoring drive. On the interception near the goal line, he also failed to see where linebacker DeAndre Levy was positioned as Driver ran a slant toward the middle of the end zone.

"I think experience is the greatest teacher of all,” Philbin said. “We can put these guys in situations – put them on the chalkboard, put them in the gym, put them in a walk-through, put them in practice out there – but until you get out there and you get a chance to do it, live bullets so to speak, it’s hard to project exactly how a guy is going to respond. I think by and large, he did a good job.”

Ugly numbers
Whether it was Rodgers or Flynn at quarterback, the numbers on Sunday for the offense weren’t good – just 13 first downs, 258 total yards, 2-of-13 on third and fourth downs, five negative runs, four sacks and three turnovers. The 13 first downs and two conversions tied for season lows and the three turnovers were a first for the offense this season. The Packers had a season-high four turnovers in a game, coincidentally against Detroit in Week 4, but two of those came from the special teams.

McCarthy took the blame on Monday for the team’s preparation, but he also said after reviewing the film that “the issues were clearly execution” because the Lions weren’t tricking-up their defensive alignments, pressures or coverages.

“I give credit to Detroit and their defense, they did a fine job against us,” McCarthy said. “But from a pure scheme standpoint, they played pretty much their base defense, and it was our guys against your guys.”

Philbin said after the game and reiterated on Monday that he can’t remember a game since he joined the Green Bay coaching staff in 2003 when an opponent ran fewer blitzes or pressure packages outside of base calls.

“They executed their defense well,” Philbin said. “They played a couple different coverages, but everybody usually does that during the course of a game. It was not an X-and-O game, that’s for sure. It was an execution game, and they certainly executed their defense well.”

A small wrinkle
Twice in the first half, Detroit quarterback Drew Stanton ran a modern-day college-like option play out of the shotgun, holding out the ball as if to hand off, but pulling it back in and taking off running around the end. He gained 15 yards on the first one and 17 on the second one, counting for the majority of his 44 yards rushing.

Defensive coordinator Dom Capers said the Lions hadn’t run that type of option play all season, so the defense wasn’t prepared for it. Stanton was making just his third career start and second this season.

“It does slow you down a little bit,” Capers said. “We made an adjustment during the game, and I think if they had run it again, we would have been fine on it. But we hadn’t practiced that. It was something we hadn’t seen, and they got us twice on it.”

Capers added that it’s a bit surprising to see an NFL team run that, but depending on the type of quarterback under center, it could become another wrinkle pro offenses explore, like the “Wildcat” formation of recent years.

“Most of the time you aren’t going to expose your quarterback to keeping the thing, because if people are ready for it, you’re going to have somebody coming after the quarterback,” Capers said. “If you’re going to expose him, we’re going to try to hit him.

“That’s something you have to deal with in college all the time because there are so many running quarterbacks, but you don’t see it much in the NFL. I think you’ll probably see more of it as we move along.”

Playoff scenarios
Without getting into all the endless possibilities, there are essentially two circumstances the Packers can hope for with regards to making the playoffs this season.

The first would be to enter the Week 17 matchup with Chicago at Lambeau Field tied with the Bears for the NFC North Division lead. If that’s the case, and the Packers beat the Bears, Green Bay is the division champ and is guaranteed at least one home playoff game.

There are other scenarios by which the Packers could enter that final meeting one game behind the Bears, beat them to forge a tie, and be declared division champs based on other tiebreakers, but that depends almost entirely on the Bears losing to the Vikings next week because Chicago has yet to lose a division game. With the loss in Detroit on Sunday, the Packers have now lost two division games.

If a division title doesn’t work out, the Packers’ next-best chance is to go either 2-1 or 3-0 over the last three games, beating the New York Giants along the way, and hoping they’re in a tiebreaker scenario with the NFC East runner-up for the final Wild Card spot. If the Packers have wins over the Philadelphia Eagles (Week 1) and then the Giants in their back pocket, they would win a head-to-head tiebreaker with either of those teams for a Wild Card.

But the play of the New Orleans Saints (10-3) and Tampa Bay Buccaneers (8-5) also will factor in, because if there is a three-way tie for one Wild Card spot, the Packers’ aforementioned head-to-head wins over NFC East teams won’t matter. Conference record would, and right now that tiebreaker is not in Green Bay’s favor, with the Packers just 6-4 against NFC teams.

More on injuries
The knee sprains to linebacker Frank Zombo and guard Daryn Colledge are of different severities, McCarthy reported. Zombo’s likely will keep him out of this week’s game at New England, while Colledge has a chance to play.

Colledge left Sunday’s game after the first offensive series when he hurt his knee trying to tackle Detroit’s Brandon McDonald on a fumble return. He hasn’t missed a game in his pro or college career, a streak now at 132 games (80 with Packers, including playoffs; 52 with Boise State).

Zombo was replaced in the second half of Sunday’s game by Erik Walden, who was signed back in Week 8. With Clay Matthews unable to practice during team (11-on-11) periods the last several weeks, Walden has already been taking Matthews’ practice reps. If Zombo is out, Diyral Briggs would be the other outside linebacker taking snaps with the first unit in practice.

Also, McCarthy said defensive end Cullen Jenkins (calf) will be “challenged” to make it back either this week or next week. Jenkins missed Sunday’s game in Detroit and has missed two games this season so far.

“It’s just something that’s tricky because you have to let it heal first,” Jenkins said. “You never know when that’s going to be. You can be feeling bad one day and two days later all of a sudden you start feeling a whole lot better. You just have to wait for that turnaround point.”

Jenkins added that it’s “tough to tell” if he’ll be able to make it back by the end of the season, but he’s holding out hope and does believe it’s possible, which is why he hasn’t gone on injured reserve.