The Chicago Cubs can ill afford to lose winnable games at this stage in the season.

They entered Monday night’s series opener against the Pittsburgh Pirates five games over .500 — as high over .500 as they’ve been since May 21 — and three games back of the Atlanta Braves for the last National League wild card spot. With the Braves on an off-day, the Cubs had an opportunity to cut their wild-card deficit to 2 1/2 games with 24 left to play.

They took advantage of that opportunity for most of Monday’s contest, too.

Jameson Taillon put together arguably his best performance of the season, rolling 11 ground ball outs as he pitched seven innings of scoreless ball. Dansby Swanson‘s solo home run in the third and Ian Happ‘s two-run triple in the fifth were enough to give the Cubs a three-run lead heading into the eighth, when manager Craig Counsell handed the ball off to Jorge López.

López has been lights out ever since he was added to the active roster on June 28. From that day through Sunday, he posted a 0.76 ERA in 21 appearances with the Cubs, the fifth-lowest ERA among qualified MLB relievers during that stretch. He went from being released by the New York Mets to being an integral part of the Cubs’ bullpen.

Unfortunately, López managed to hold the lead for just eight pitches.

Pittsburgh’s Isiah Kiner-Falefa led off with a blooper for a base hit, followed by Nick Gonzales legging out a slow roller to third base. On pitch No. 8 from López, Bryan Reynolds snuck a high four-seamer into the front of the left-field bleachers to tie up the game. Two batters later, Andrew McCutchen launched an inside sinker into the bleachers, giving the Pirates a lead they wouldn’t relinquish in the Cubs’ 5-3 loss.

“[López] made a couple good pitches to the first two hitters, and they found some holes,” Counsell said. “And then he left some fastballs just in the big part of the plate.”

The obvious question after a loss like that is if Counsell should’ve stuck with Taillon, who cruised through his seven frames on only 89 pitches. That’s obviously operating in hindsight, but it’s a fair question nonetheless.

But again, López has been excellent for the Cubs over the last two months, and with Pirates hitters about to go through the order for the fourth time, it seemed to be a logical spot for Counsell to go to one of his most-trusted relievers. He just couldn’t get the job done.

“There was a reason we gave [Taillon] an extra day,” Counsell said. “And look, we put Jorge López in the game. He’s been wonderful. He’s pitched wonderfully. He obviously didn’t have a good night tonight, but that was the decision. And it was an easy decision.”

“It’s always just a tough spot to be in as a manager,” Taillon said. “Flipping the lineup over there, I mean, I understand it. López has been one of the best relievers in baseball ever since we got him over here. He’s been lights out. Also, just kind of a weird inning, obviously. Cutch put a great swing on a good pitch, and then Reynolds is a great player, but to get the runners on base in front of him, it was a bloop and an infield hit or whatever.

“So, just unfortunate, but I understand it. I wasn’t in there pounding the table trying to stay in or anything. When you hear Jorge López is coming in behind you, it’s like, ‘Yeah, that’s one of our dudes.’ He’s one of our leverage guys, and he’s been doing it. It just is what it is.”

Considering they’ll be facing Paul Skenes, Pittsburgh’s rookie phenom, Tuesday night, picking up a win Monday felt even more necessary. So, this loss feels like a missed opportunity for the Cubs to continue clawing their way up the standings.

Would Counsell agree with that sentiment?

“It feels like a loss,” he said. “I mean, we lost. We didn’t get it done tonight.”

Regardless, the Cubs let a potential win slip through their fingers, snapping their six-game winning streak in the process. Add in the postgame news that Justin Steele was scratched from his start Tuesday due to elbow soreness and will be replaced with Kyle Hendricks — who’s posted an 11.12 ERA in three starts against the Pirates this season — and this feels even more like a game they needed to win.

The season is still not over, of course, not with roughly four more weeks left to play. But time is running out, and the Cubs are 10 games back in the division and 3 1/2 back in the wild card race. Not only will they need the teams ahead of them in the standings to drop a few more games, but they’ll also need to take care of their own business.

They didn’t do that Monday, so they now have to turn the page and make sure they don’t let a game like that slip away again.

“We’re in a situation now where we’re chasing,” Counsell said. “That’s what we’re doing — we’re chasing. And that in itself creates urgency. It just does, and that’s good. It kind of does it for you, almost. And so, that’s how we have to play. We know we have to play at a really high level, because we’ve got significant ground still to make up. But we’ve also, in a sense, earned this, and we’ve earned the right to have some fun this month and to play some good baseball and see what happens.”