PORT ST. LUCIE — The Mets produced a solid turnout Monday at their voluntary pre-camp with one of the more interesting situations being the development of center fielders Juan Lagares and Michael Conforto.

Both were present. Lagares has reshaped his swing, working with noted swing doctor Craig Wallenbrock this offseason. The results were there for all to see. Lagares has added loft to his right-handed swing in an effort to drive the ball. He was doing exactly that during his batting practice session, a big change from the line-drive swing he used to have. Wallenbrock has had great success with free agent J.D. Martinez and the Dodgers’ Chris Taylor.

Lagares needed to change it up.

With 1,770 plate appearances over his five years in the majors, Lagares owns a .257/.297/.366 slash line.

“It feels good,’’ Lagares said of the change.

He will get plenty of time in center with Conforto recovering from surgery to repair the torn posterior capsule in his left shoulder. Conforto is here early too, but said he has not been cleared to swing a bat.

“I don’t know when I will be back,’’ Conforto said. “But everything is coming along great, better than expected.’’

Last month general manager Sandy Alderson said Conforto is not expected back before the first of May, but Conforto did not want to put a timetable on his return.

Conforto knows the key is not to push it too quickly as he returns from such delicate surgery. Manager Mickey Callaway was able to speak to both players as he gets to know his team.

Jacob deGrom threw another impressive bullpen session to catcher Travis d’Arnaud. In addition, shortstop Amed Rosario participated in the workout on Field 2 of the complex with a couple dozen players, many of them minor leaguers.

Infielder Phil Evans put on a strong display during batting practice and pitcher Chris Flexen, who made nine starts last season, also participated in the workout.

Free agent Lucas Duda was spotted at the camp although he did not participate with the Mets’ players.

Callaway’s entire staff is expected to be in Port St. Lucie on Tuesday, as they go over final plans for spring training. More players are expected to arrive daily.