Ten disastrous minutes separated the Chicago Cubs from the cusp of ending a season-high losing streak to their worst loss of the season.

A five-run lead entering the bottom of the eighth should have provided enough cushion for the Cubs to put away the Houston Astros. Instead they departed Minute Maid Park ahead of Thursday’s day off with a crushing 7-6 walk-off loss that raised more questions about how the Cubs bullpen can get on track.

The Cubs (19-24) head to Philadelphia, where they kick off the last leg of their three-city, nine-game trip Friday carrying a five-game losing streak.

“We’ve got to cash that win in,” manager David Ross said. “You’re trying to set guys up for success and match up things that go well, and it didn’t go well tonight. So you’ve got to look at it. Go back to the drawing board and continue to have those guys work.”

Mark Leiter Jr., pitching for the second time in 10 days, allowed two runs in the eighth and struck out three. Keegan Thompson was called on for the ninth against the Astros’ 7-8-9 hitters with a 6-3 lead.

Within three pitches, the Cubs advantage was whittled to a run courtesy of Jake Meyers’ two-run homer. A full-count walk to pinch hitter Mauricio Dubón ended Thompson’s night.

Thompson says he doesn’t feel any different from a season ago, when he posted a 1.47 ERA in 36 relief innings. As the Cubs try to maximize Thompson’s usage and how his body recovers after pitching, they have not yet been able to deploy him in the same manner.

All 12 of his 2022 relief appearances were at least two innings with the majority lasting three. Only six of his 15 outings this year have gone multiple innings.

For the Cubs bullpen to function within how it was built entering the season, they need the 2022 version of Thompson, both in usage and performance. Without his ability to take down multiple innings, an already unproven relief group is further thrust into uncertain roles.

“We’re trying to get him synced up when he’s got enough rest, it feels like something we’ve got to look at just him bouncing back a little bit better,” Ross said of Thompson “It’s got to be better.”

Traffic on the bases has been a constant problem for the right-hander, even when he tosses zeros.

Through 15 appearances, Thompson has allowed at least one baserunner in all but one game. The lone exception came in his previous appearance Sunday in Minnesota. Thompson has walked 14 and struck out 16 in 21⅓ innings while allowing 14 hits.

Thompson doesn’t believe the quality of his stuff has been an issue.

“Things aren’t going my way right now,” he said. “Just had some hard contact today. It’s a punch in my gut. It just sucks to let the team down.

“I‘ve done the exact same stuff the whole time, and some of them haven’t been working out. It’s just tough to go through some of those hard times right now.”

Ross did not waste time getting Brandon Hughes up in the bullpen. The lefty began warming up after Astros catcher Yainer Díaz’s first-pitch leadoff single in the ninth. The prompt decision highlights the urgency of the moment and Ross knowing he needed to have a lefty ready for the top of the order, in preparation for Thompson facing the minimum threebatter requirement.

“They jumped on him early with a couple pitches there and then scared him out of the zone,” Ross said. “Walked a guy, I’m not going to wait around at that point.”

Hughes surrendered a double to Jeremy Peña and intentionally walked Alex Bregman to load the bases with nobody out. After getting a force out at home, Hughes gave up Kyle Tucker’s walk-off, two-run single to center. Christopher Morel’s throw home nearly nabbed Bregman, but Yan Gomes’ tag was a fraction late. The Astros’ game-winning play at the plate underwent replay review and was confirmed.

“The boys played well enough for a win and we didn’t do our job,” Hughes said, “so it hurts.”

The blown lead squandered Drew Smyly’s stellar outing in which he limited the Astros to one run in six innings. Seiya Suzuki (two home runs) and Morel (home run) led the offense.

“This game has a way of making things spiral on you, individually and as a team, and you have to hold your belief that things will turn around, that you’re good enough, that it all evens out in the end,” Smyly said. “Right now it’s a tough stretch. But we have an off day. Hopefully we can clear our heads and try to play better in Philly.”

Thompson’s inconsistency from outing to outing is compounding Ross’ limited high-leverage options.

The Cubs’ two offseason signings for veteran relievers have not panned out well seven weeks in.

Brad Boxberger, who is going back to Chicago for further evaluation of his right forearm strain, has struggled all year and Michael Fulmer hasn’t been able to get on a roll amid some unluckiness, posting a 59 ERA+ and .375 Batting Average on Balls in Play (BABIP). Thompson hasn’t thrown enough competitive pitches around the zone. Hughes has already been on the injured list twice. Nick Burdi and Jeremiah Estrada don’t possess much big-league track experience. Michael Rucker and Julian Merryweather have a mixed track record in leverage opportunities. Adbert Alozlay’s performance could earn him more chances in big spots on top of his multi-inning flexibility; he’s surrendered an earned run in just four of his 18 appearances.

As the Cubs struggle to get on track, losers in 18 of their last 25 games, they must weigh how long they can let Thompson try to work through his struggles at the major-league level versus Triple A. They need him to get right and pitch more like the reliever they saw in 2021 and 2022.

The Cubs are in dangerous spot, squandering a strong start in what is setting up to be a winnable division could quickly put them in a bad position. If the Cubs rip off winning streaks — or at the very least play .500 for a prolonged stretch — the front office could be in sell mode again this summer.

“We’re just excited to get out of this city,” Smyly said of Houston. “We’ve seen enough of it. Ready to get home.”