Mets starter Robert Gsellman delivers against the Nationals at Citi Field...

Mets starter Robert Gsellman delivers against the Nationals at Citi Field on Aug. 11. Credit: Jim McIsaac

DENVER — As the healthy Mets fight the clock in their attempt to make the playoffs, a pair of injured Mets are fighting the clock in an attempt to get back by the end of the regular season — which is a week from this Sunday.

Robert Gsellman (partially torn right lat) threw a “nice and easy” bullpen session Sunday, he said, and might do another Tuesday at Coors Field. Dominic Smith (left foot stress fracture) relocated his rehab process to the Mets’ facility in Port St. Lucie, Florida, since the major-league team is out of town all week.

On the injured list since Aug. 17, Gsellman made 10 throws off the mound at Citi Field, his first time doing so since getting hurt. He is still hoping to pitch this season but said he is “trying not to get ahead of myself.” He noted that it would be valuable to return even for one relief appearance, if only for the peace of mind of being a healthy, normal player heading into the offseason.

“That’s a huge step for anybody, to come back and get an inning in at the end of the season, for mentality, for overall feel for the offseason, knowing you’re not hurt anymore,” Gsellman said. “I would feel great from it.”

Manager Mickey Callaway said Smith is readying to face live pitching, in the former of minor-league pitchers at the Mets’ instructional league, “at some point.”

“It’s not going to be [Monday], but he’s in Florida prepping for that,” Callaway said.

A new Noah plan

The Mets plan to have Rene Rivera catch Noah Syndergaard on Wednesday, according to multiple reports.

That is the latest twist in the strange saga of Syndergaard and his batterymates. Syndergaard repeatedly has expressed his preference for Rivera or Tomas Nido to the Mets, who after that became public last week stuck him with Wilson Ramos on Friday. Now, the Mets seem ready to relent.

Alonso earns thanks

In a letter addressed to Pete Alonso and posted to Twitter, the Police Benevolent Association of the City of New York thanked Alonso for leading the Mets’ wearing of 9/11 tribute cleats last Wednesday.

“We share your disappointment that Major League Baseball refused to support your efforts,” the letter read in part, “and we appreciate the determination you showed in making sure your teammates could still honor our heroes.”

The NYC PBA also noted that the Mets as an organization have “consistently gone above and beyond to help support the men and women of the NYPD.”

“We are truly lucky that they have a young star of the game helping to keep that tradition alive,” it said.

Lowrie sits some more

Jed Lowrie remains a candidate to start games, Callaway said, but that Lowrie hasn’t done so yet is more a matter of him not being a better option than other Mets, not his ability to play nine innings.

“It’s more just being out for so long, these games mean so much, that’s a tough order,” Callaway said. “There’s still a chance he’ll do it at some point.”

Since being activated from the IL on Sept. 7, Lowrie had three pinch-hit at-bats entering play Monday.

Extra bases

Alonso, batting fifth Monday, made his first start below the No. 4 spot. Callaway said that had more to do with a desire to stack four lefthanded hitters at the top of the lineup — against Rockies righthander Antonio Senzatela, who especially struggles against lefties — than Alonso’s recent slump. He was 0-for-his-last-20 with 10 strikeouts heading into the Colorado series . . . After ending up with the Sunday night game, the Mets arrived at their Denver hotel around 3 a.m. Monday. “It wasn’t bad,” Callaway said. “We do that all the time.”