DETROIT — After the tumult of the trade deadline and the Subway Series and the Yoenis Cespedes injury and golf-playing situation, the Mets finally had a baseball-only day on Friday.

Terry Collins even managed to crack a smile when jokes were made about Cespedes hitting the links during his injury rehab in Port St. Lucie, Florida. He hasn’t. Cespedes has put his clubs away, as far as anyone knows.

All that was left was a juicy pitching matchup: Noah Syndergaard vs. Justin Verlander.

Unfortunately for the Mets, Verlander was dominant and Syndergaard was so-so again. The Mets managed only five hits and struck out 12 times against Verlander and three relievers as the Tigers took a 4-3 decision before 33,032 at Comerica Park.

Syndergaard (9-6) allowed four runs in six innings, including a go-ahead two-run homer by Victor Martinez in the fourth after Kelly Johnson had given the Mets their only lead with a two-run homer in the top of the inning. Johnson had been 0-for-15 against Verlander.

“It was kind of funny,” said Syndergaard, who was not laughing. “As soon as we took the lead, that was great, awesome hit by Kelly, and I went out there in the fourth inning just thinking in my head, ‘Don’t give up the lead. Don’t give up the lead.’ It was just like trying to tell someone to not think about a pink elephant. It doesn’t work out like that. So I dropped the ball on that one mentally. That can’t happen.”

Syndergaard last won on July 3. The Mets are concerned about his high pitch counts (112 on Friday) and his lack of extra oomph since the All-Star break.

“It’s been a battle,” Collins said. “That’s a great way to put it. He’s had to work very, very hard, harder than he ever probably has had since he’s been a major-league pitcher. To be honest, even though it’s tough, I think it’s good for him. If you’re going to learn to pitch at this level, you’ve got to learn to pitch through tough times, and right now he’s going through tough times. He got ahead of a lot of guys and couldn’t make the pitch to get them out.”

At least Syndergaard hasn’t lost his confidence.

“One thing he’s not lacking is swagger,” Collins said.

Once the lead was gone, the Mets did not recover. They went 0-for-5 with an RBI with runners in scoring position, with all of those at-bats coming in the second and ninth innings.

The Tigers had gotten on the board in the first when Ian Kinsler singled, stole second and third and scored on a slow chopper to third by Miguel Cabrera. The Mets chose to play the infield back with one out and Cabrera at the plate, and it cost them.

In the fourth, Johnson hooked a Verlander curveball into the rightfield seats for a two-run homer to give the Mets a 2-1 lead.

But the Tigers got the lead back two batters into the bottom of the inning. Cabrera singled and Martinez unloaded a two-run homer to right to make it 3-2.

J.D. Martinez followed with a double and scored three batters later on James McCann’s two-out single on an 0-and-2 pitch to cap the Tigers’ three-run inning. Syndergaard was not pleased about the 0-and-2 pitch becoming a run.

“Right now, I’m trying to be too fine with all of my pitches,” he said. “Trying to basically play darts out there to me as opposed to going out there and trusting my mechanics and just delivering a quality pitch.”

Verlander (12-6) gave up two runs and four hits in six innings with one walk and nine strikeouts. The Mets scored a run in the ninth against Francisco Rodriguez (31st save) on James Loney’s groundout.