His scruffy beard.
"It seemed like it was time," Fitzpatrick said Wednesday. "Switch up the mojo a little bit."
He might have a point.
Fitzpatrick made headlines last November when he shaved his beard while starting for the Houston Texans. A few days later, he played the game of his life, throwing six touchdowns in a rout of the Tennessee Titans.
The well-traveled quarterback claimed that had no bearing on this week's decision. Aside from the mojo factor, he said he did it to look younger; he celebrated his 33rd birthday on Tuesday.
For the record, the beard isn't history. It's just ... well, less unwieldy.
Fitzpatrick also made a joking reference to Buffalo Bills coach Rex Ryan. Before facing the Jets two weeks ago, Ryan cracked, "The thing that's disappointing to me is that beard. I mean, you look at him like, 'Really, kid?' So he's not a real handsome kid."
Fitzpatrick said he wanted to open with a Ryan joke at the start of his Wednesday media session. Reporters urged him to tell the joke anyway, and so he did.
"This is what I was going to open with," he said.
He paused, trying to keep a straight face.
"Well, after the last few games, I decided I needed to look in the mirror and just try to figure out what I can do better," Fitzpatrick said. "When I looked in the mirror, I realized Rex was correct, and I was pretty ugly. And I think this is a better look for me right now."
It has been a rough patch for Fitzpatrick, who has thrown four interceptions in the past two games. The Jets (5-5), who face the Miami Dolphins (4-6) on Sunday, have dropped four of their past five. Fitzpatrick received a vote of confidence this week from coach Todd Bowles, but he could be running out of chances.
Fitzpatrick still has the respect of his teammates -- even without the usual amount of facial hair.
"It's difficult to see a good beard go down," said center Nick Mangold, now the proud owner of the bushiest beard on the team.
Fitzpatrick polled his teammates, asking the question: To shave or not to shave? Wide receiver Brandon Marshall said it was a close vote.
"It was a team effort," he said. "I think we made the right decision."