PORT CHARLOTTE, Fla. — As the Yankees and Rays finished a 5-5, nine-inning tie Thursday, Jordan Montgomery sat in the clubhouse checking his phone, his long legs spilling out over a pair of chairs.

The 6-6 lefty, who had just wowed Yankees brass in his first start of spring training, looked as if he didn’t have a care in the world.

Looked the same way on the mound.

Montgomery thrust himself squarely into the battle for one of the last two spots in the Yankees’ rotation by striking out eight Rays, including Evan Longoria twice, in an impressive 4 1⁄3-inning outing at Charlotte Sports Park.

Montgomery was charged with two runs, but one scored after he left the game with a runner on first base. He gave up three hits and walked none. For a 24-year-old who knew he was pitching with a chance to go from curiosity to candidate, he was remarkably calm and composed. And Montgomery’s stuff was really good. Fastballs from 93-95 mph plus a changeup, curve and slider. Command and control.

“He’s got four pitches he commands on the mound,” Austin Romine said. “He likes pitching in, which is a rare thing in a young guy coming up. When you’ve got a guy with that much pitchability, there’s so many things you can do to get guys out. It was fun to catch. He was pretty impressive.”

Montgomery, a fourth-round pick in the 2014 draft, went 14-5 with a 2.13 ERA in 25 starts between Double-A and Triple-A last season. At the higher level, he was 5-1, 0.97.

advertisement | advertise on newsday

Still, he was hardly on the radar for a big-league look when camp opened. No one from the righthanded group of Luis Severino, Adam Warren, Bryan Mitchell and Luis Cessa has made Girardi swoon, though, so Montgomery got a chance to show he might belong.

“I’ve always believed in myself,” Montgomery said. “I’ve always practiced with a chip on my shoulder, lifted with a chip on my shoulder, everything, because everyone always doubts me and I know what I can do.”

Said Girardi: “I thought he threw really well. I did. I thought he had swings and misses on his fastball, on his slider. I thought his changeup was good, I thought his curveball was good . . . Interesting case.”

The Yankees have seven exhibition games left. Girardi said he hadn’t mapped out when or if Montgomery will get another start before the season opener April 2 at Tampa Bay.

“I liked what I saw,” Girardi said. “So we still have seven, eight days to figure this out. I liked what I saw — a lot.”

Yankees videos

Montgomery struck out two in each of the first two innings and the side in the fourth. He allowed a run in the second, when Steven Souza Jr. tripled on a looping drive to rightfield that just eluded the diving Aaron Judge and scored on a sacrifice fly.

In the first inning, Montgomery struck out Longoria on a 93-mph fastball. The plan in that at-bat, Romine said, was simple: “Heaters. Went right at him.”

In the fourth, Montgomery got ahead 0-and-2 on Longoria, the Rays’ best hitter and a perennial Yankee-killer, before the count went to 3-and-2. Another heater? No, Montgomery broke off a slider that Longoria swung over for strike three.

The person who was least impressed with Montgomery was Montgomery. He said he wasn’t pitching while envisioning himself on the mound at Yankee Stadium (which he has been to once, on a tour when he played for the Staten Island Yankees in 2014). He said he wasn’t trying to win a job in the big leagues.

“Just still playing baseball,” he said. “Just trying to go out there, do my job and throw strikes and get people out.”

advertisement | advertise on newsday

And the way he went after Longoria? As Montgomery thumbed through his phone, it didn’t look as if he were replaying the at-bats in his mind. A few minutes later, that fact was confirmed.

“I can’t even remember what I threw to him,” he said. “I threw like 60 pitches out there. It’s hard to remember them all.”