On a day the Mets lost another outfielder to the injured list, Mickey Callaway said Brandon Nimmo is still “a ways away” from getting into any games.

Nimmo has not played since May 20 because of a bulging cervical disc in his neck. While he recently started baseball activities again after being shut down for 30 days, he is still in the beginning stages of his comeback.

“He’s doing more and more hitting off a tee, hitting in the cage, things like that, running around, taking fly balls,” Callaway said before the Mets topped the Pirates 3-0. “Just normal baseball activity at this point.”

Steven Matz’s complete game gave Edwin Diaz another night to rest his big toe, which got drilled by a Manny Machado line drive on Thursday.

Diaz was throwing in the bullpen briefly in the ninth inning, a night after Seth Lugo handled the closer’s job. Callaway said he was “pretty confident” Diaz would be available, but also recognized the value in giving him an extra day off.

“Diaz is coming off the foot thing, so it’s good to get him another day,” Callaway said. “Lugo’s thrown two days in a row. [Justin] Wilson was used [Friday] night. [Robert] Gsellman was used [Friday] night. We really needed Matz to do that.”

Another reliever who has stepped into a high-leverage role is Luis Avilan.

After a rough start to the season, which he capped by spending nearly two months on the injured list with elbow soreness, Avilan has been earning work in bigger situations of late. The veteran lefty has thrown eight straight scoreless outings since returning from the IL on July 2.

The Mets entered Saturday with a 2.83 ERA since the All-Star break — the lowest mark in the National League in that stretch — and Avilan has played a key part in that.

“Having both lefties and having Avilan pitching well to where you can trust him to go in and get some big outs in big situations is huge for our bullpen,” Callaway said.

Callaway fell to 11-12 in challenges this season. He asked for one when Wilson Ramos grounded out to third base in the second inning, thinking first baseman Josh Bell had stepped off the bag early. But the call stood after replay review.

J.D. Davis’ seventh-inning home run was his 10th of the year. The Mets now have eight batters with double-digit home runs. Only the 2017 Mets (10) had more players in double figures in club history.