Mets starter Jacob deGrom delivers a pitch against the Miami...

Mets starter Jacob deGrom delivers a pitch against the Miami Marlins during the first inning at Citi Field on Sunday, Aug. 20, 2017. Credit: Kathleen Malone-Van Dyke

Jacob deGrom has been a rare bright spot in an otherwise lackluster Mets season, and he now is targeting a milestone that hasn’t been reached by any of the club’s other highly touted starting pitchers: 200 innings in a season.

DeGrom has thrown 165 innings, including 6 1⁄3 Sunday in a 6-4 loss to the Marlins at Citi Field. He looked strong for most of the game before a rough final inning. After allowing two runs in six innings, he gave up three more in the seventh, finishing his day with eight strikeouts. The Marlins had 10 hits and no walks against him.

DeGrom (13-7, 3.49 ERA) said he is turning his attention to finishing the season strong and hitting that 200-inning mark.

“That was a goal coming into the year, trying to get there,” said deGrom, who is third in the majors in innings pitched behind Chris Sale (175 1⁄3) and Chris Archer (166 1⁄3). He threw 191 innings in 2015, but this already is the second-largest workload of his four-year career.

Bartolo Colon was the last Met to clear the 200-inning threshold when he threw 202 1⁄3 in 2014. Among the team’s collection of prized young pitchers (deGrom, Noah Syndergaard, Matt Harvey, Steven Matz and Zack Wheeler), deGrom came the closest to reaching this mark in 2015.

Seasons of 200 innings are becoming rarer, so this is not something exclusive to the Mets. Last season, only 15 starters cleared this bar, the fewest in a non-strike-shortened season since the 1800s.

Still, if deGrom were to accomplish this feat, it would help his season further stand out from the other members of the rotation. Syndergaard has not been healthy (he has made only five starts), Matz has not been effective (he has a 6.08 ERA) and Harvey has been neither (5.25 ERA in 13 starts).

“At this point in the season, after missing what he did last year at the end of the season, he’s trying to certainly get 200 innings,” Terry Collins said. “I know that’s a big part of what he wants to do this year.”

DeGrom missed most of last September because of an elbow issue, and 2016 was the first season in which he struck out less than a batter per inning. This season, his strikeout rate is back in elite territory, 10.4 batters per nine innings.

This was the second straight outing in which deGrom allowed five runs, and Collins said fatigue is a possible factor.

“[GM Sandy Alderson] addressed it one day when he said, ‘We’re going to be careful with him down the stretch,’ ” Collins said. “He always is deep in the game. There might be a little fatigue in there.”

DeGrom has thrown at least six innings in 20 of his 25 starts. He’s taking a simple approach the final month: “Just keep going out there every fifth day.”