There are times when pitching for the Mets seems like a job suited only for the most daring of thrill-seekers. How long can you go on a margin of error so thin that it threatens to blow away with one strong gust?

This was the situation faced by Jacob deGrom on Thursday, and then Jeurys Familia. The first pitcher thrived, the latter pitcher buckled, and the result was a 2-1 loss to the Rockies, courtesy of two ninth-inning runs. It was the second straight game in which the Mets entered the ninth with the lead and left with a loss.

“Our pitchers live on the edge,” manager Terry Collins said. “It’s hard to do every night . . . We could have blown that game open with two ground balls and we weren’t able to do it. That’s what it comes down to.”

In a slow-motion nightmare that not even this reeling team saw coming, Familia and the Mets’ defense fell apart in the ninth. Before Wednesday night’s blown save against the Cardinals, Familia had converted his last 52 regular-season save opportunities. On Thursday, he began a streak of another kind, notching his second blown save in a row.

Collins had said Familia would be unavailable to pitch, but Familia spoke to him in the morning to say he was willing and able.

“I don’t have excuses,” Familia said. “Everybody played hard. We’ll get them tomorrow. We have to play better tomorrow.”

Trevor Story led off the ninth with a single and stole second before David Dahl walked. That was followed by a series of misplays.

After bunting foul twice, Daniel Descalso bunted the 0-and-2 pitch and the ball stopped in front of catcher Rene Rivera, who waited for it to go foul . . . except it stayed on the chalk, loading the bases with none out. Familia struck out Tony Wolters, but when Cristhian Adames hit a slow roller to the right side, the ball skipped off the leg of James Loney, who had ranged between first and second, for an error as the tying run scored. Familia then bounced a wild pitch past Rivera, making it 2-1.

Familia got out of a bases-loaded, one-out jam, but the damage had been done, and the Mets went down in order in the bottom of the ninth. “It’s tough,” Rivera said. “Stuff happens, you know? . . . This is baseball and you’re going to have tough stretches and [Familia] just hit two . . . It’s one of those games that you have to bounce back.”

It’s unfair to lay all this at Familia’s feet, though. The Mets stranded a runner at third in the fourth and fifth and loaded the bases with none out in the seventh, but Kelly Johnson grounded into a force at the plate, Curtis Granderson struck out and Wilmer Flores flied to center.

The Mets entered the game hitting a major league-low .206 with runners in scoring position and went 1-for-9, stranding nine runners. They scored their only run in the second when Loney singled with two outs and scored on a double by Rivera, who tried to stretch it into a triple and was out by about five feet.

DeGrom, who lowered his ERA to 2.56, continued to prove that even if his offense is in tatters, and even if his velocity is down from last year, he still can deal. He allowed no runs, five hits and a walk in seven innings, striking out six. It should have been enough, but not for this team.

“Driving in runs is mental,” Collins said. “The approach you have at the plate, your mindset of all you’re trying to do is put the bat on the ball . . . We’re just not doing it.”