DENVER — Robert Gsellman is “very” optimistic he can pitch again for the Mets this season, based on a recent progression in throwing.

The right-hander threw about 10 pitches in a bullpen session before the Mets opened a series against the Rockies on Monday and is prepared to repeat the process this week. Gsellman indicated if he passes that test he could see action in a simulated game by the weekend.

Would Gsellman’s potential return hinge upon whether the Mets are still alive in the NL wild-card race?

“We haven’t talked about that yet, but we probably will at some point,” Gsellman said.

Manager Mickey Callaway indicated it’s probably not too late for Gsellman, who has been on the injured list since since Aug. 14 with a partially torn lat.

“I think anything is possible,” Callaway said. “It depends on how you want to use him.”

Callaway shuffled the lineup against the Rockies to get four left-handers — Brandon Nimmo, Jeff McNeil, Michael Conforto and Robinson Cano — at the top. Pete Alonso was dropped to fifth for the first time this season, but Callaway said that switch was more about stacking the left-handers than the fact Alonso entered in an 0-for-20, the longest slump of his career. Left-handers were batting .349 against Rockies starting pitcher Antonio Senzatela, prompting the lineup change.

Dominic Smith, who is recovering from a stress fracture in his left foot, traveled to Port St. Lucie to increase his baseball activities, according to Callaway. Smith, who has been sidelined since late July, is not eligible for removal from the 60-day IL until Sept. 25. At that time he will have to receive a scan on the foot before he is cleared to resume. Smith will likely begin taking batting practice in Port St. Lucie, according to Callaway.

J.D. Davis crashed into the left-field fence in the eighth inning but remained in the game, saying he got the wind knocked out of him. Among those to check on Davis was Alonso, who jogged out from first base. Alonso said he had to check on the “Sun Bear” — evidently the complement to Alonso, who carries the “Polar Bear” nickname.

After playing the ESPN Sunday night game the Mets didn’t arrive to their hotel until about 3 a.m. local time, but Callaway downplayed the team’s travel and turnaround.

“That is what we were told to do,” Callaway said. “We can’t make the schedule, we just can play it. Baseball is a grind and that’s a grind, but we’ll do it and see if we can’t get a win.”

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