Cobb was injured when tackled by Tennessee's Tracy Wilson while returning a punt with 8:38 left in the third quarter -- a game in which Cobb set the franchise single-season record for all-purpose yardage. On his previous two punt returns, Cobb had gained 14 and 17 yards.
"I'll be honest with you: I don't have a really high tolerance for this [line of questioning] because I don't understand how you play scared in the game of football. I don't get that," McCarthy said sternly. "I think it's convenient questioning. I understand the risk involved in every single play. Some plays are higher risk than others, and I'm fully aware of that.
"But you can't sit here and say special teams is important if you don't put a guy like Randall Cobb out there as a returner. Now, if we're sitting here next year, we might be having a different conversation. But the way our team is built for 2012, Randall Cobb is a huge part of our success on special teams."
McCarthy didn't have any update on Cobb's health, although he said Cobb seemed optimistic and the team's medical staff wasn't overly concerned, either. Cobb was scheduled to undergo further testing Monday.
"He may be in there as we speak. Then the doctors will determine what scans (are) needed, and we'll get that information sometime today," said McCarthy, who held his day-after-the-game news conference at 8 a.m. CST because of Christmas Eve. "The medical staff does not have high concern. Randall's so positive, so he doesn't seem very concerned. But you go through the process and scans and so forth and make sure we get all the information."
Even with quarterback Aaron Rodgers' not-so-subtle post-game suggestion that Cobb is too valuable to risk on returns, McCarthy said Cobb remains the returner, including in next Sunday's regular-season finale at Minnesota if he's available. After Cobb went down, first-year wide receiver Jeremy Ross had a 58-yard punt return that set up Ryan Grant's 7-yard touchdown run on the next play.
After the game, Rodgers was asked about Cobb's overall performance, and spoke of Cobb's role on returns.
"He's a big time player," Rodgers said. "He's fun to watch. Just trying to get him the ball in space. He makes some big plays. He's got incredible preparation habits. He's always ready to play, knows where he's supposed to be. He's like a seven or eight-year veteran out there, it feels like at times. I feel like we've played together for a while. He understands the concepts we're running, where to get open. He's a big-time player."
Then, after a brief pause and with a slight grin, Rodgers added, "[I] hope we can get him off special teams soon."
Although McCarthy responded in his post-game press conference with "We'll see" when first asked about Cobb staying on returns, the coach wasn't coy a day later.
"Randall Cobb is a big part of our success on special teams. Our special teams has been our most consistent unit of our football team from Week 1 to Week 15. You don't establish the way you play, the vision of the way you play, and then all of a sudden change going into the last week of the season," McCarthy said. "We'll see what happens here with Randall and we'll evaluate his injury and then we'll make decisions as we go forward. The philosophy of him playing on special teams has not changed."
Since McCarthy took over as head coach in 2006, the Packers have not been afraid to use starters and key contributors on offense or defense as returners. Defensive backs Charles Woodson and Tramon Williams have been in that role, as has wide receiver Jordy Nelson.
McCarthy has never back down from that stance, even when Woodson suffered a toe injury on a punt return against Detroit during the 2007 season. Woodson missed a critical game against the Dallas Cowboys the next week.
Woodson returned 74 punts during the 2006 and 2007 seasons.
As a rookie second-round pick last season, Cobb's primary role was as the team's kick and punt returner; he finished the season with a 27.7-yard kickoff return average (second in the NFL, including a team-record 108-yard return for a touchdown) and 11.3-yard punt return average (seventh in the NFL, including an 80-yard return for a touchdown).
But Cobb has unexpectedly emerged as the Packers' No. 1 receiving threat this season, leading the team in receptions (80) and yards (954), while Nelson and Greg Jennings have been sidelined for lengthy spells with injuries. Cobb has returned 38 kickoffs for a 25.4-yard average with a long of 46, and he's returned 31 punts for a 9.4-yard average, including a 75-yard touchdown.
Special teams coordinator Shawn Slocum was not available to reporters Monday. But before the season, with the offensive coaches planning on using Cobb more extensively, Slocum said the risk to Cobb on returns is no greater than it is on plays from scrimmage.
"It's all in the perspective, of how you look at the return game. It is the first play of the offense? It's vitally important to setting up field position, the potential to score, things of that nature," Slocum said. "
"It's no different than when he catches a pass on offense and people tackle him (as far as the risk). He can have great production in the return game. What happens is, when you have a returner who can score, he can affect how the ball is kicked to you as well, which can give you favorable field position.
"Here's the thing: There are really three areas of special teams that directly influence winning and losing statistically: made field goals, explosive returns, and keeping opponents from having explosive returns against you. If you take care of those three areas, and you win in those three areas, you're giving yourself a better chance to win as a football team.
" So special teams play, the way we look at it, is very important."