LONDON -- After the Cubs’ victory in the London Series opener against the rival Cardinals, manager David Ross had some advice for anyone who could grab tickets for Sunday’s game at London Stadium.

“They've gotta come out and see the Stro Show,” Ross said.

Unfortunately for Chicago, the show only lasted into the fourth inning due to a combination of poor defense and a pesky injury. Marcus Stroman exited the marquee event four batters into the fourth after a blister on the index finger of his pitching hand became problematic in the Cubs' 7-5 loss.

• Best moments from London Series Game 2

Stroman left before the blister broke open and sounded optimistic. Based on similar setbacks earlier in his career, he might not have to miss a turn in the rotation. The Cubs will monitor how his finger heals and responds to treatment in the coming days before making any official decisions on that front.

“I think I should be good,” Stroman said. “I’ve got two more starts before the break, and then I think that break should give me some time to heal and rest for a bit.”

For the Cubs, it was a disappointing finish to a memorable weekend trip across the pond. After an overwhelming 9-1 win over the Cardinals on Saturday night, the North Siders were off to the airport after splitting the I-55 Derby (to borrow from the style of great Premier League rivalries).

• 4 artifacts from '23 London Series to be enshrined in HOF

“It stinks to end on this note,” Cubs first baseman Trey Mancini said. “Because, I mean, it's been just one of the coolest experiences of my life. And I think a lot of other guys would say the same thing.”

In the series finale, fans had the chance to see Stroman, who has been one of baseball’s top starters this season. And he was excited for a chance to pitch in front of the announced crowd of 55,565.

“The stage is incredible,” he said.

Stroman entered the day as the National League’s leader in ERA and with the most quality starts (14) in baseball. He looked the part in the first inning, when he ended things by snaring a grounder from Lars Nootbaar and starting a 1-6-3 double play. Stroman celebrated with a little shuffle on the mound before heading to the dugout.

Stroman is the Cubs’ top All-Star candidate and a candidate to start for the NL. About that possibility, Stroman said, “The biggest thing for me is to be as healthy as possible and to pitch for this team,” as Chicago tries to chase down the division-leading Reds.

“He's a guy that loves the spotlight,” Ross said. “He's been our MVP of our team, I would say.”

That is why what followed was alarming for the Cubs and their fans.

Stroman was shaking his hand multiple times throughout the fourth. The righty appeared especially bothered through a sequence of allowing a single to Tommy Edman, hitting Brendan Donovan with a pitch and then giving up an RBI single to Paul Goldschmidt.

After Goldschmidt’s hit pushed the Cardinals in front, 5-4, Stroman glanced back at the Cubs’ dugout as he made his way to the mound. He was met by a member of Chicago’s training staff and Ross, eventually departing the game before the issue worsened.

“Honestly, it felt like it was gonna rip any pitch in those last few innings,” said Stroman, who noted that the issue started during his pregame mound workout. “Other than that, I felt pretty good. I just felt like they did a good job of putting the ball in play and hitting in early counts.”

When the smoke cleared, Stroman’s line featured six runs allowed (three earned), increasing his ERA to 2.47 from 2.28. Entering the afternoon, Stroman was 7-0 with a 1.29 ERA in his previous seven turns.

Things went sideways for Stroman and the Cubs in the second.

With two outs and the bases loaded, Stroman induced a grounder off the bat of Edman that second baseman Nico Hoerner collected and fired to first. Mancini arrived late and made an awkward attempt to catch the ball with his bare hand. The baseball dropped to the dirt, a run scored and Donovan followed with a two-run single.

It was a miscue that opened the door for the Cardinals to erase the 4-0 lead the Cubs built in the first inning. That opening rally featured a two-run double by Mancini.

“The double doesn't matter at all,” Mancini said. “I kind of let the game speed me up there and the game is 100% on me. I'm sorry to my teammates and all the fans, because it's been such a great trip here and it would’ve been nice to get two wins.”