Rodgers was expected to begin the evaluation protocol for head injuries Monday. The quarterback's availability for Sunday night's game at New England remains unclear.
"We're not going to take any chances," McCarthy said. "No different than on game day. When it became a question, an issue -- was he clear, wasn't he clear? -- we pulled him immediately. We'll always take the high side of caution in these types of situations."
Rodgers also sustained a concussion in Green Bay's loss at Washington on Oct. 10. He played against Miami the next week and has not missed a game since taking over as the Packers' starter in 2008.
McCarthy said doctors will consider Rodgers' recent concussion as they evaluate him.
"He's just getting ready to start to go through the first procedure, first process of the testing and so forth," McCarthy said Monday. "They had him sleep in this morning, and I just had a chance to visit with him. We'll go through the protocol that we do with all of our players, and we'll probably have a little better update for you Wednesday or Thursday."
According to NFL guidelines for head injuries, Rodgers must be symptom-free and cleared by a team doctor and independent neurological consultant before he can play again.
But the team's biggest concern by far will be Rodgers.
"We've got to make sure, No. 1, that Aaron is healthy and take care of him," wide receiver Greg Jennings said after Sunday's game. "He's the priority. Health is first and foremost. You can't risk it all because you want to play a game. We understand that. As an offense, we just have to come together and refocus and rededicate ourselves on the practice field."
Rodgers is well on his way to becoming one of the league's elite quarterbacks, but he still needs to learn to slide out of danger when he takes off running.
"We probably need to do a better job of getting that across because the quarterbacks can't be taking unnecessary hits like that," McCarthy said.
Facing significant pass-rush pressure from the Lions, Flynn was 15 of 26 for 177 yards with an interception in relief of Rodgers. Flynn said he will be ready if Rodgers can't play Sunday.
"We'll see what happens, but I'm going to prepare the hardest I've ever prepared," Flynn said. "Because obviously I made a couple of mental mistakes that shouldn't happen, especially in tough situations when those things can't happen."
"We hope we have Aaron back; he's a special athlete," Matthews said. "But at the same time, this has been the story of the Green Bay Packers this year -- having guys step up. We've been able to play with the players we have and do a good job."
Copyright 2010 by The Associated Press