Did we just get a glimpse at Mets’ Opening Day lineup?

Juan Lagares, Amed Rosario and Jeff McNeil Anthony J. Causi (3)PORT ST. LUCIE — Dress rehearsals have begun.

Other than the starting pitcher — and the fact a designated hitter was in play — the lineup manager Mickey Callaway unveiled Sunday could very well be employed when the Mets open their season on March 28 in Washington.

There was Jeff McNeil at third base for the first time this spring, as Jed Lowrie and Todd Frazier remain sidelined with injuries. Brandon Nimmo was in the leadoff spot against the Cardinals and playing left field. Juan Lagares was in center. Dominic Smith and Pete Alonso both started (the latter was the DH), and one of the two likely will open the season at first base.…