The injury bug has struck the Eagles again. This time it got the most important player on the roster, quarterback Donovan McNabb, who suffered a cracked rib while rushing for a three-yard touch down in the third quarter of Sunday’s season opener victory against the Carolina Panthers.

After getting tackled in the endzone, McNabb laid on the ground for several minutes before walking off the field on his own power. He immediately headed into to the locker room to get examined by the Eagles trainers. He did eventually return to the field, but did not return to the game. He was seen on the sideline without his pads, at times looking dejected and frustrated, other times he was seen laughing it up with teammates.

“He’s not going to get much sleep these next few days,” said running back Brian Westbrook, who broke a rib last season. “But Donovan’s a tough guy.”

An injured McNabb is nothing new for Eagles fans, but Week 1 is a little earlier than we’ve become accustomed to. While many expected that Michael Vick would take over should McNabb go down this season, he is not eligible to play for the Eagles for another two weeks. That means that should McNabb not be able to go next Sunday for the home opener against the New Orleans Saints, the starting job would fall to Kevin Kolb.

“Well, I think I can go in there and show leadership,” Kolb said after today’s game. “The biggest thing for a backup quarterback is leadership. Not let the offense miss a beat. Just come in there and run it as smooth as it was before the injury and keep us clicking.”

After McNabb went down around seven minutes into the third quarter, Kolb stepped in and attempted to keep an offense that had already scored 24 points going full steam ahead. Unfortunately, while he did manage to complete seven of his 11 passes, Kolb was sacked twice and fumbled twice, and the Eagles weren’t able to put any more points on the board.

Kolb has struggled as McNabb’s backup in his two plus years with the Eagles. His attempt to backup McNabb last season against the Baltimore Ravens has been well documented. The numbers: 10-for-23, for 73 yards, with two interceptions, including one returned 105 yards for a touchdown. His QB rating was 15.3.

McNabb was struggling through much of last season up to that point and the benching of Number Five was seen as an attempt to shake things up by coach Andy Reid. If Kolb had played better, then maybe McNabb wouldn’t haven gotten the start the following game against the Arizona Cardinals on Thanksgiving night, and who knows how the rest of the season might have turned out.

“I’ll definitely be excited (if he gets the start),” Kolb said. “I’m also a huge fan of Donovan’s and I hope the best for him. He’s a tough guy and he’ll fight through it if he can.”