PHILADELPHIA -- No longer “strictly a second baseman,” as Mickey Callaway defined him early last summer, Jeff McNeil demonstrated his chops at third base Monday with two diving stops late in the game -- one to start a key 5-4-3 double play in the eighth inning, limiting the damage in a game-tying rally, and another to help preserve a tie game in the ninth.

“Pretty comfortable,” was how McNeil, who has split his defensive time between third base and left field, described his comfort at the former position. “I’m taking as many reps there as possible.”

For McNeil and J.D. Davis, however, circumstances are about to change. While the Mets haven’t yet activated Todd Frazier from the disabled list, his rehab assignment will expire on April 23. When Frazier returns, the reps available for other players at third base will dwindle. Whenever Jed Lowrie returns from the sprained left knee ligament that has kept him out all season, those opportunities will reduce even further.

To combat a potential loss in playing time, Davis began taking outfield reps last week for the first time since joining the Mets this winter. While Davis appeared in 25 games in the outfield between the Majors and Minors last season, he feels less comfortable there than at third and first base. But Davis sees outfield work as his ticket to continued at-bats once the infield mix becomes more crowded.

“The more versatile you can become, the more chance you’re in the lineup,” Davis said. “So I’m just getting more reps out there, getting more and more comfortable.”

Same goes for McNeil, who has played plenty of left this season but is still adapting to the position. The Mets, however, have reason to keep McNeil in the lineup no matter what their infield mix: he entered Tuesday’s play fifth in the Majors with a .404 average.

As for Frazier, the infielder was back in Class A St. Lucie’s lineup on Tuesday, marking the 10th game of his rehab assignment. The earliest Frazier could rejoin the Mets would be Friday in St. Louis.

The Edwin Edicts

Callaway said Tuesday that the Mets’ restrictions on closer Edwin Diaz -- he’ll pitch in the ninth inning or later only, and never for more than three outs at a time -- have nothing to do with the bone spur in his elbow.

Mets officials were reportedly aware of the spur when they acquired Diaz from the Mariners this winter. They were also aware that Diaz, like many pitchers with similar issues, has pitched through it for years without issue.

Instead, the Mets’ treatment of Diaz is strategic. They maintain faith in Jeurys Familia, Seth Lugo, Robert Gsellman and others, and believe that bullpen corps gives them the luxury of protecting Diaz as much as possible.

“It’s not health related,” Callaway said. “It’s just setting guys up for success. He had a lot of success in the role he was in last year, and we feel that him having that role for us, like he did last night -- he came in and struck three guys out and looked electric -- is going to be the spot that we feel like we need to put him.”

Last year, Diaz led the Majors with 57 saves in 61 chances, but he extended beyond three outs to record them on just three occasions.