PORT ST. LUCIE — Zack Wheeler can look on the bright side: He’s already on the team.

If the Mets right-hander had turned in the kind of performance last spring training he had on Monday against the Marlins, he might have been more concerned about the implications. This one, he could shrug off.

“I’ve still got to go out there and prove myself, but at the same time I’m going out there and working on what I need to work on to get better and prepare for the season,” Wheeler said after allowing six earned runs over 1 ²/₃ innings in the Mets’ 13-2 exhibition loss at Tradition Field.

Was Wheeler really concerned about not making the team last spring?

“Yeah, for the most part,” he said. “I was still young and had only pitched half-a-season, so I still had a lot to prove.”

He is now a major component of a Mets rotation that also features Matt Harvey and Jacob deGrom, with veterans Bartolo Colon and Jon Niese behind him.

Wheeler breezed through the first inning on Monday, but plunked two batters in the second and allowed two hits and two walks. Manager Terry Collins yanked him after he had thrown his 37th pitch of the inning, a fastball that drilled Derek Dietrich.

“His command was off, but plus stuff,” Collins said. “I think the two hit batters, a lot of it was due to the fact he was throwing about 96, and he was pitching in and just made balls inside, they couldn’t get out of the way of them.

“But that is not an excuse for the fact he didn’t have his command in the second inning, and as I’ve, we’ve seen thus far in this camp, when you walk guys the gates are going to open up.”

A day earlier, Niese pitched two strong innings, but was gassed in the third, when he allowed two earned runs against the Red Sox. It came after Colon, Harvey and deGrom had largely dominated in their initial starts of the Grapefruit League season.

Wheeler said switching from the windup to the stretch in the second inning Monday was an issue.

“[But] I was happy with the outing overall,” Wheeler said. “I did hit two batters and walk a couple, but it’s still early and fastball command was a little off. Offspeed was there, it was sharp and I was throwing strikes, so that part I was happy with.”

Wheeler went 11-11 with a 3.54 ERA in 32 starts for the Mets last season. His best work came over the final three months of the season, when he went 8-3 with a 2.71 ERA.

Earlier this spring, Collins specifically mentioned Wheeler as a candidate to pitch the opener in Washington on April 6, but has another eight days to a chart a course. Following an off day on March 18, the manager must align his rotation to get the pitchers on proper rest for the start of the regular season.

The only pitcher Collins has eliminated from consideration for the opener in Washington is Harvey, who missed last season rehabbing from Tommy John surgery.

But Wheeler might want to show more in his scheduled start Saturday against the Nationals if he wants to stay in contention for the honor.

“I saw outstanding stuff today and I told Zack, ‘I’m not worried about anything, you will get it going, just be patient and continue to work on the side with release point, so you get a little bit better command of his fastball,’ ” Collins said. “But his stuff is still very good, and I think as we get deeper into camp we’ll see the guy we know we’ve got.”