PORT ST. LUCIE, Fla. — Zack Wheeler has earned a spot in the New York Mets' rotation after missing two years while recovering from Tommy John surgery, and Robert Gsellman will begin the season as the team's No. 5 starter in place of the injured Steven Matz.

Manager Terry Collins made the pitching decisions Thursday. Collins also said centre fielder Juan Lagares is going to the disabled list because of an oblique strain and outfielder Michael Conforto will be with the Mets on opening day.

Collins chose to use Wheeler in a role he is familiar with rather than send him to the bullpen. Gsellman is scheduled to pitch out of the bullpen in the first couple of games before starting for the Mets on April 9.

"We felt like we needed to start the motor a little bit (on Zack)," said Collins, who had mentioned Wheeler as a bullpen candidate. "The bullpen is really a bad role if you haven't pitched in two years. We said, 'Let's run him out there.'"

He will follow Noah Syndergaard, Jacob deGrom and Matt Harvey in the imposing rotation. Wheeler's first start since 2014 will be against Miami on April 7.

Gsellman had a 2.31 E.R.A. this spring, best among all the starting pitchers. He said he tried to avoid finding out his fate — either starting or relieving — by avoiding social media.

"I didn't listen to (social media). I waited until someone told me. I was really happy because I had a good spring. I didn't want to get ahead of myself and be cocky," said Gsellman, who was a big part of the Mets' success late in 2016.

Matz has been shut down for three weeks with a tender left elbow, another in a series of injuries that has beset the young left-hander. Slated to be the team's No. 4 starter, Matz will possibly stay in Port St. Lucie into early May.

"I don't know if I have the words for it — I'm disappointed. For two years, we've talked about this rotation, and if we could keep them healthy, we're second to none. We have five guys who have legitimate No. 1, No. 2 (starter) kind of stuff," Collins said.

Conforto will be the team's fourth outfielder and first left-handed bat off the bench.

"Terry called me in this morning and gave me the situation. I'm going to be coming off the bench and be a pinch-hitter late in the game. He's going to try and get as many at-bats for me as possible," Conforto said.

Josh Smoker and Josh Edgin also earned roster spots, giving the club three left-handed relievers along with Jerry Blevins.

"It's definitely something I've always dreamed about as a kid. I mean, not many people get the chance to experience opening day on the field as a player," said Smoker, a Calhoun, Georgia, native who will be in the opposite dugout of his childhood favourite team on Monday, the Atlanta Braves.

Edgin, who rehabbed from Tommy John surgery, has been with the Mets his entire pro career. Out of options, he likely would not have passed through waivers and been claimed by another team.

"It's rewarding. Spring training didn't start out like I wanted, but I made some adjustments," Edgin said. "My family is 100 per cent behind me, regardless of what happened."

Collins said the final roster spot will go to either Seth Lugo or Rafael Montero. Lugo was impressive in the WBC while Montero was outstanding in the Grapefruit League.

Both will pitch in the next two days. Collins said one will make the roster and be in the bullpen on Monday against Atlanta; the other will go to Las Vegas and prepare in a starting capacity in case of emergency.

Non-roster player Ty Kelly and Bronx native T.J. Rivera also broke camp with the team as backup infielders. Both played in the WBC — Kelly for Israel, Rivera for runner-up Puerto Rico.

NOTES: Collins said 1B Lucas Duda (hamstring) will be ready for opening day. Duda complained of tightness Monday morning and was scratched from the game against the team's Triple-A affiliate in Las Vegas. . RHP Matt Harvey will stay behind a day and pitch in a minor league game on Friday in the warmth of Florida rather than New York.