CLEARWATER, Fla. — Jordan Montgomery was a very long shot to make the Yankees’ pitching staff when spring training opened.

Thursday, the 24-year-old left-hander will start against the Rays in Port Charlotte with a chance to force himself onto the 25-man roster.

Granted, the chance is tiny, but the Yankees aren’t ruling it out.

“It’s possible,’’ Joe Girardi said Wednesday when asked if the 6-foot-6 Montgomery could make the team, which opens the regular season against the Rays on April 2. “Either role.’’

Montgomery has made 56 of his 60 minor league appearances as a starter and his last relief outing was in 2015, but Girardi hasn’t completely ruled out bullpen work for the hurler, who threw four scoreless innings against the Tigers in relief on Friday. All four of his spring outings have been in relief.

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A fourth-round pick in 2014 from South Carolina, Montgomery isn’t on the 40-man roster and has made six starts above Double-A, so the smart money is on his returning to Triple-A Scranton/Wilkes-Barre and starting. If Montgomery does well, he could force his way into the big leagues at some point.

Still, the fact that the five-man battle for the final two spots in the rotation hasn’t produced even one clear-cut winner this late in camp means the Yankees are open to at least looking at Montgomery. He went a combined 14-5 with a 2.13 ERA and fanned 134 in 139 ¹/₃ innings for Double-A Trenton and SWB a year ago.

“I’m a work in progress,’’ said Montgomery, who brings a 3.48 ERA into Thursday’s game. “I’ve been more on the map each year. I try to keep on working hard and play baseball the right way and carrying myself the right way.’’

Asked if anybody has told him that he is in the mix for a big league roster spot, Montgomery said, “They told me I’m pitching [Thursday] and I’m taking it day by day.’’

Thanks to his height, Montgomery creates the downhill angle pitching gurus love to see. And while his changeup hasn’t been as good as it was last year, his toolbox — which includes a fastball that reaches 94 mph, a slider and a curveball — is solid.

At the beginning of camp, Girardi didn’t know much more than the sparkling numbers Montgomery posted last year.

Now?

“I like him a lot. He has a really good downward angle and deception. I’m very curious,’’ Girardi said. “He’s 6-foot-6 and gets on top of the ball. You talk about deception, there can be a lot of different ways. Some guys hide the ball, some guys’ motion is really easy and a short arm and gets on top of hitters quickly. He is a guy who is tall and changes planes, and I think that’s part of his deception.’’

Luis Severino and Bryan Mitchell were the favorites to claim the two open rotation spots when camp opened. Severino hasn’t been good, and Mitchell has been just OK. Adam Warren likely is headed to the bullpen, and Luis Cessa and Chad Green are strong candidates to start at SWB.

Whether Montgomery can show the Yankees enough in the short time left that he can help as a starter or reliever in the big leagues is a long shot. But not as long as it was when pitchers and catchers reported in February.