NEW YORK -- When 6-foot-6, 225-pound Jordan Montgomery showed up at the University of South Carolina in 2012, he hadn't fully grown into his body.

“I was uncoordinated,” Montgomery said.

His teammates pounced on his gangly frame and slapped the nickname "Gumby" on his back. He rolled with it and a funny thing happened: Montgomery matured into his body, and the New York Yankees took him in the fourth round of the 2014 MLB draft.

Just three years later, he might have earned an upgraded moniker. He might be turning into this generation’s version of Andy Pettitte. None other than Yankees manager -- and Pettitte teammate -- Joe Girardi made the comparison.

“Their stuff is different, but Andy Pettitte,” Girardi said when asked whom he'd compare Montgomery to among past pinstripers.

The numbers back it up, as Montgomery, a lefty like Pettitte, is 6-4 with a 3.62 ERA in 15 starts. As a 23-year-old rookie in 1995, Pettitte went 12-9 with a 4.17 ERA in 26 starts (31 appearances). If you projected the 24-year-old Montgomery’s performance over 31 starts this year, he would finish with a 12-8 record and a 3.62 ERA. At his current pace, Montgomery would end up at 178 innings pitched. Pettitte threw 175.

"It is not cockiness. It is not showboating. It is just quiet confidence, knowing he can get the job done."

Montgomery could finish second to Aaron Judge for the American League Rookie of the Year Award. Pettitte was third in the 1995 rookie race behind the Twins' Marty Cordova and the Angels’ Garret Anderson.

In June, Montgomery went 4-0 with a 2.59 ERA. No Yankees starter has had as good a month as a rookie since Stan Bahnsen in 1968. Bahnsen was the Rookie of the Year that season.

Montgomery has a full menu of pitches with the ability to go to a fastball, change, curve, sinker and slider. His release point, which is nearly 7 feet, is higher than any starter in baseball this season.

“For whatever reason, I don’t think people see him very well,” Girardi said. “That’s really important at this level.”

When Judge describes his fellow rookie, he talks about the "it" factor. Judge noticed Montgomery’s extra gear last season, at Triple-A, when the lefty finished 14-5 with a 2.13 ERA.

“[He has] that quiet confidence to know you can do it,” Judge said. “He is going to go out there and get the job done. He is going to go out there and he has confidence in his stuff. It is not cockiness. It is not showboating. It is just quiet confidence, knowing he can get the job done.”

The confidence showed during the spring. In the fight for the No. 5 spot in the rotation, Montgomery wasn't up for consideration at the beginning of camp. Girardi knew Montgomery had a tremendous season at Triple-A in 2016 but thought he was a guy who'd contribute at some point later in the season.

As camp wore on and no one took hold of the No. 5 job, Girardi began to pay more attention to Montgomery. The manager was particularly impressed with how unflappable Montgomery stayed even when he fell behind in counts.

While Montgomery wasn’t on the Yankees’ initial radar, he never lost confidence. In fact, in his mind, he was all but the favorite.

“I thought I deserved it,” Montgomery said matter of factly. “But I didn’t think other people thought I did. If they are not going to do it, you have to throw well enough so they have to.”

Montgomery did just that, throwing 19⅔ innings and posting a 3.20 ERA. He left the Yankees with little choice other than to move up their timeline on his promotion.

“I didn’t have anything left to prove at Triple-A,” Montgomery said.

As it turns out, he has been the best new starter in all of MLB. He has been overshadowed by Judge’s epic performance, but when it comes to winning down the stretch -- and possibly in the playoffs -- Montgomery might be just as important.

These days, most of his teammates call him Monty, which is a go-to for pro ballplayers, who will just add a “y” to nearly anyone’s name. The Gumby moniker hasn’t completely died, though; Montgomery’s Twitter handle is @GumbyNation34.

“He’s a big Gumby,” Judge said.

He might be, but he also might be the next Andy Pettitte.