But in Tampa Bay, if you're a backup quarterback, chances are at some point you're going to play.
And Gradkowski and McCown both know that, which is why their battle for the No. 2 position tonight against Houston is so important.
One of them may have to play in Garcia's place this season.
"That will be something I'm sure that we have to make a tough decision on," Buccaneers head coach Jon Gruden said.
Tampa Bay has used three starting quarterbacks two of the past three seasons. Gruden would like nothing more than to see Garcia make it through the entire season. But the reality is that Garcia is 37 years old, and Gruden must have someone prepared to move into the role if Garcia misses any time.
Most pegged Chris Simms for that role entering training camp. But given Simms' slow progress this preseason, he may not even make the football team.
Enter Gradkowski and McCown, who each have had solid preseasons.
"I feel confident coming in there with all those other guys and we're just making plays," Gradkowski said.
Gradkowski, like last preseason, has come on late. He led the Buccaneers to two touchdowns on his first two drives of the game last week against Miami. He finished 10-of-16 for 104 yards and two touchdowns.
Entering tonight's game Gradkowski is 23-of-38 passing for 267 yards, 3 touchdowns and no interceptions.
Gruden senses a comfort level in the second-year pro that he didn't a year ago when he was forced to use him as a rookie for an injured Simms.
"Experience is a great teacher," Gruden said. "He's clearly a lot further along than he was a year ago, and I think Jeff Garcia has really helped the development of Bruce and certainly Luke [McCown] because they all play the game with a spontaneous style sometimes."
Garcia, Gradkowski and McCown are all mobile quarterbacks who have shown a penchant for making plays on the run.
McCown rose quickly from No. 4 to No. 2 during training camp and started the preseason with a perfect performance against New England — 7-of-7 for 68 yards and a touchdown pass.
It was McCown's first game action — preseason or otherwise — in two years.
His performance has dropped slightly since, but he's 21-of-30 for 191 yards and a touchdown.
McCown entered the game midway through the second quarter last Saturday, leading the Bucs to a Matt Bryant field goal on his second possession. It felt like a missed opportunity, though, as the drive was set up by a Dolphins turnover.
"We would have liked to get a touchdown out of that last drive, but we got three points and that's positive," McCown said.
McCown went 5-of-10 for 57 yards against the Dolphins.
Throughout camp and preseason, McCown has kept an even keel and he refuses to be sucked into talk of a competition.
"We're going to compete and I'm going to go out and put my best foot forward either way, take the reps the coaches give me and it's about this team, not this competition — who's No. 2 and who's No. 3," McCown said. "It's about the team and about winning."
Gruden hasn't said whether Garcia will play tonight, but it's likely he won't play. That means it's likely McCown or Gradkowski will start with the first team, and that both will see plenty of playing time in the first half.
And that may be the determining factor in who begins the season as Garcia's backup.
Matthew Postins covers the Buccaneers for BucsBlitz.com and the Charlotte Sun-Herald in Port Charlotte, Fla. He is a member of the Pro Football Writers Association and has won national awards for his Buccaneers coverage from the PFWA, the National Newspaper Association and the Associated Press Sports Editors. He is also a contributor to the Scot Brantley Show from 4-7 p.m. weekdays on WHBO 1490-AM in Tampa-Clearwater.