It was an impressive showing from an offense that entered Sunday near the league average in runs scored per game. A power-hitting lineup in the past, they had just 23 home runs, the fifth-lowest in baseball, because Bruce, Frazier and Conforto, who is returning from shoulder surgery, had combined for only six homers — though Frazier added one in the eighth inning on Sunday. (Frazier and Conforto have been more effective at drawing walks.)

“It’s not always about having the big numbers; it’s about getting the key hits,” Gonzalez said.

In an effort to bolster the offense, Callaway said he would give more playing time to the backup outfielder Brandon Nimmo, who has hit well in limited chances. That would mean Bruce would play at first base “every now and again,” Callaway said, along with Wilmer Flores and Gonzalez, who have thus far formed a platoon at the position.

“I came into this year knowing I’m not the everyday guy and I’m just ready to go whenever they call me,” Gonzalez said.

Gonzalez, 35, a veteran left-handed hitter with a balky back and a one-year contract, and Flores, a right-handed hitter, both entered Sunday’s game batting .200 or lower. Advanced metrics, however, showed Gonzalez was hitting the ball better than his numbers indicated.

“It’s for the benefit of everyone to keep Adrian rested and to make sure Nimmo gets in the game as much as he should be playing and keep Bruce in there as often as possible,” Callaway said. “It’s a fine balance.”

On the mound, the Mets’ rotation had a 4.13 earned run average entering Sunday, 15th in baseball — a low figure for a group that was expected to be among the best in the N.L. entering this season.

The Mets are 9-3 in games started by deGrom (2.06 E.R.A.) and Syndergaard (2.86 E.R.A.) but 8-6 in games started by anyone else. Matt Harvey was moved to the bullpen to keep Wheeler in the rotation and to make room for the newcomer Jason Vargas.