Credit: Getty Images / Rob Foldy

In the days before we knew how to pronounce “Gsellman,” and the little-known Seth Lugo was a StatCast curiosity due to his hellacious spin rate, the Mets still planned to have their rotation driving the bus back to October.

And when we say rotation, we mean the guys from the spring-training photo, minus Matt Harvey, who was the first to step down with thoracic outlet syndrome. That all seems so naive now. For a month, the Mets pushed the illusion of Jacob deGrom and Steven Matz returning in some capacity, only to later admit their next appearance would be on an operating table rather than the mound.

None of us should have been fooled. This sort of medical sleight of hand has been going on for a long while with the Mets, and pretending deGrom or Matz eventually was going to make it back didn’t seem to do them any good, either. The amazing part? Those losses haven’t crippled their playoff chances — thanks to Lugo and Gsellman, who also may be capable of helping the Mets defend their NL crown a little longer than we anticipated.

Lugo is 5-1 with a 2.68 ERA in his eight starts after piloting the Mets to a 5-2 victory over the Marlins Wednesday night. He was adequate, allowing two earned runs over 5 1⁄3 innings, and did a nice job shaking off Martin Prado’s two-run homer in the first inning. But after 82 pitches, Terry Collins said he didn’t want this one slipping away. Plus, Lugo could probably use the breather. His next assignment, barring any complicated tiebreaker scenarios, would be against the Cubs in the Division Series.

“This kid has come here and done nothing but saved us,” Collins said afterward. “Him and Robert.”

Gsellman has a 2.56 ERA in six starts and one relief appearance, and is coming off seven scoreless innings in Sunday’s 17-0 win over the Phillies, whom he faces again in tonight’s series opener. These aren’t Cy Young campaigns. But as long as the Mets keep riding their battering-ram offense, just getting adequate performances from both might be enough to stretch this season. Lugo insists he’s ready for what’s next.

“I expect a lot of adrenaline,” Lugo said. “That helps.”

The Mets haven’t locked up as much as a wild-card berth yet, but after taking two of three in Miami, and with Philly’s putrid bullpen waiting at Citizens Bank Park, we’re ready to pencil them in. Assuming Noah Syndergaard beats the Giants or the Cardinals in that wild-card game, it will be up to 43-year-old Bartolo Colon — then Lugo and Gsellman — to tackle the Cubs.

It’s a tall order, obviously. But sizing up the Mets’ weakened rotation reminds us of 2006, when Willie Randolph’s 97-win team, a World Series favorite, got dealt a brutal double-whammy during the week leading up to the playoffs. First they watched Pedro Martinez go down with a torn tendon in his calf muscle during the final days of the regular season. Then Orlando Hernandez, on the eve of NLDS Game 1 at Shea, strained his calf running sprints in the outfield.

This season, at least, they’ve had more advance warning. Back then, Randolph was forced to go to John Maine, who had been the fifth starter, along with the disappointing Oliver Perez (6.38 ERA) as complementary pieces to Tom Glavine and Steve Trachsel. Knowing what you do about Maine and Perez, are the Mets really that bad off having to rely on Lugo and Gsellman this year? Again, they still have some business to take care of in Philly. But Collins’ faith in these two has definitely grown in the past few weeks.

“They’ve pitched well enough that look, you have to have confidence if you get there, anybody can win,” Collins said. “Somebody has to step up and pitch good. Why can’t it be our guy? That’s the way I look at it.”

The Mets don’t have a choice. Either Lugo and Gsellman are up to the task, or this whole title defense ultimately falls apart at Wrigley. We trust that Syndergaard and this re-energized lineup can get the Mets that far. From there, it’s going to be up to them.

Newsday LogoSUBSCRIBEUnlimited Digital AccessOnly 25¢for 5 months
ACT NOWSALE ENDS SOON | CANCEL ANYTIME