NEW YORK — Many Cubs fans treat each night almost like it’s Game 7 of the World Series.

And that’s understandable — that’s part of what being a fan is.

But David Ross can’t manage that way.

Even if he wants to.

“I think my heart, my competitiveness is always chasing a win,” he said.

When Ross is standing on the top step of the dugout and witnessing his bullpen cover 12-15 outs a game for two-and-a-half months, he knows it’s not sustainable over the course of a full, 162-game season.

Especially this year, where everybody is treading cautiously regarding pitcher workloads following 2020’s shortened slate.

The Cubs rank 20th in baseball in rotation innings, averaging a shade under 5 innings per start. That includes Kyle Hendricks, who averages 5.7 innings per start.

The bullpen has been a strength of this team and an enormous reason why the Cubs woke up Thursday morning in 1st place. They lead Major League Baseball in relief ERA (2.55) but have also accounted for the 4th most innings of any unit in the game.

That’s why we see some instances like Wednesday night where Ross let Robert Stock work out of his own jam even though the spot starter was clearly struggling with his command. The inning started with the Cubs trailing by only 2 runs (3-1) and Jacob deGrom had just exited the game.

Stock wound up getting out of the inning, but not until he surrendered 2 more runs.

“If I know we’re getting 7 a night out of the starters, then I would probably be a little more aggressive down 2, to be honest with you,” Ross said. “How we built success and wins this year and why we’re in 1st place is a big part of that bullpen so protecting that asset is important to me.”

With Wednesday in specific, Ross didn’t have many options at his disposal.

Adbert Alzolay, Trevor Williams and Justin Steele are on the injured list — though all are nearing a return — and the Cubs called up Stock from Triple-A to help fill an immediate need in the rotation. They also promoted Cory Abbott, but he started Iowa’s game Sunday and threw 94 pitches.

Alec Mills got the start Tuesday night in New York and Keegan Thompson backed him up with 2 innings in relief, so both “long” guys in the Cubs bullpen were unavailable. Rex Brothers had just worked the first 2 games of the series and the only rested pitchers were also the Cubs’ top relievers that have been pushed hard this season so far (Craig Kimbrel, Andrew Chafin, Ryan Tepera, Dan Winkler).

Ross takes all of this into account on a daily basis.

“In a down game, I think sometimes it’s just really difficult to push those guys that you might need the following day,” Ross said. “I think it’s safe to think that Kyle Hendricks is gonna give us real length today but we don’t know that until the game happens.

“We’ve ridden those [top bullpen] arms hard when we’ve had the lead and luckily we’ve gotten a lot of leads and put some of those in the bank. But sometimes when you’re down, you gotta rely on your depth and some guys that are here.

“If I’m bringing in a Ryan Tepera down 5 in the 4th inning, I’m an idiot. I gotta try to play this as smart as I possibly can.”

Playing it smart means looking at the big picture and understanding this is a marathon season again.

If the Cubs bullpen wears down, there goes the team’s biggest strength. Ross is doing everything he can to try to ensure that does not happen and his boss appreciates it.

“He’s been A+ so far,” president of baseball operations Jed Hoyer said on Cubs Live! Thursday. “He’s been amazing. It’s easy to manage when every night is a 7-inning start, get 2 innings out of the bullpen and when guys aren’t hurt, you can run the same lineup out. And we’ve been the exact opposite all year.

“He’s had to do a brilliant job with the bullpen because our starters candidly haven’t given us enough length, so every night has been 12-15 outs out of the bullpen, which is hard to do.”

The return of Alzolay and Williams would provide a boost to the rotation and Steele’s presence would offer another reliever capable of going multiple innings.

Alzolay threw a 40-pitch bullpen Thursday as he works his way back from a blister on his pitching hand. The Cubs will see how he recovers and plot his next steps after that.

Williams (appendectomy) threw a 25-pitch bullpen Thursday. Steele (hamstring) threw off a mound Wednesday and felt fine Thursday in his recovery.

The Cubs sent Stock back to Triple-A Iowa Thursday. They will need another starter Monday against Cleveland at Wrigley Field but have not made those plans public yet.

Alec Mills is slated to get the ball for Sunday’s series finale with the Marlins. He missed time with a low back strain in mid-May that kept him out of action for a few weeks.

“Right now, depth is gold and very valuable to us,” Ross said. “Millsy gives us that — a guy that has a track record of starting and having success in the big leagues and throwing a no-hitter even.

“Now that he’s back and healthy and continuing to stretch out, it’s definitely a nice piece. That role he plays of he can be a starter, can be a long guy in the ‘pen, that sixth man in the rotation. When something happens, to fill him in that spot is a lot of value for us.”