"It's just another opportunity and another chance to go play football, which is what I love to do," McGee said. "Any chance you get to compete you can't take for granted, and certainly I'm looking forward to it."
However, things are a little different this time around.
For the first time in years, the Cowboys have a backup quarterback who is quite capable of starting for a few NFL teams, Kyle Orton. So having a third quarterback isn't such a big deal right now.
Injuries at several positions -- notably cornerback and wide receiver -- and a decision about whether to go deeper at defensive or offensive line might force the Cowboys to keep only two quarterbacks on the roster this season.
In order to change the decison-makers' minds, McGee has to play better than he has so far in in training camp and the preseason. He has completed just 58.1 percent of his passes and has zero touchdowns and one interception. To be fair, the bulk of his 31 throws have come under duress while he has been behind an inexperienced offensive line.
But working with the same line, Carpenter has thrown one touchdown pass and compiled an 84.8 quarterback rating out of 14 attempts.
In a telling sign of just where these two quarterbacks are at, McGee failed to lead the offense to a score in the Blue-White scrimmage, while Carpenter did.
The Cowboys like McGee's skill set. He's smart, mobile and has a starter's arm. His biggest issue is his inability to throw the ball downfield on a consistent basis. While admitting he'd like to do it more, McGee will tell you that playing quarterback isn't about throwing it all over the field, it's about hitting the open man.
"The biggest thing is to put the ball where it's supposed to go," McGee said. "If it's completing an 8-yard stop route because it's off coverage, that's where it's got to go. There's always what-ifs. 'Oh, this guy got open.' That's not really where the ball is supposed to go. I think the other big thing is there's going to be guys who come free and not let other people's mistakes [bother you]."
Carpenter doesn't have the same skills, but he has shown he isn't afraid to go after defenses.
"The goal is to play in the NFL for as long as you can any way you can do it," Carpenter said. "I want to be on the active roster. I want to be a part of the team, and you can't do that if you're not in the NFL."
This is Carpenter's second stint with the Cowboys. He was on the practice squad in 2009 and spent the past two seasons in Tampa Bay waiting for a chance. But he's not getting caught up in a quarterback debate.
"I've never thought of it like that," he said. "And I'm never going to. I don't want to make it bigger than what it is. My job is to go out and execute plays. That's all I can worry about. I can't control what happens."
The Cowboys knew when they selected McGee in the fourth round of the 2009 draft that there would be some developmental stages. McGee worked mostly out of the shotgun at Texas A&M, so he needed to transition to playing under center more often in the NFL game.
There was no way he was going to surpass starter Tony Romo, but he never really gave then-backup Jon Kitna a run for the backup job. In two seasons, McGee has thrown just 82 passes for 420 yards and three touchdowns with no picks.
McGee makes his case for the roster in training camp and practices, and each year he slips by and remains the No. 3 quarterback. When Kitna retired in the offseason, the Cowboys signed Orton with the hopes they upgraded the No. 2 quarterback position.
So what about McGee?
At some point, the developmental stage of a quarterback has to end and a franchise needs to see progress.
Wednesday night, McGee has to show that progress, or the Cowboys will be forced to move on without him.