Keegan Thompson has already shown he belongs here in the big leagues.

But in what role is still to be determined.

The 26-year-old rookie will receive an opportunity to show what he can do in the rotation over the final few weeks of the season and made his second big-league start Saturday at Wrigley Field.

Thompson was handed the loss in a 4-2 Cubs defeat, allowing 2 runs in 4 innings of work.

Before the outing, manager David Ross said one of the main things he was anxious to watch was how Thompson responded when the pressure was on.

“Just looking for him and find those moments where you see that competitiveness and that focus really dial it in in the biggest moments when the game could be in the balance and see how he handles those,” Ross said.

Right off the bat, Ross and Cubs fans got to see that mettle from Thompson.

He gave up a leadoff single to Whit Merrifield on a pitch that was actually off the plate and out of the zone. Two pitches later, Royals shortstop Nicky Lopez tucked a hard ground ball inside the foul line and Thompson was immediately staring down a situation with runners on second and third, nobody out and the heart of the Royals order coming to the plate.

A wild pitch brought home Merrifield but Thompson buckled down from there, getting a groundout, a strikeout and then a flyball to end the frame, limiting the damage to just the 1 run.

“I thought he did a nice job of pitching out of the jam in the 1st,” Ross said. “Second and third, nobody out, only allowing 1 run was impressive.”

All told, it was a 31-pitch 1st inning for Thompson, who was only stretched out to 61 pitches with Triple-A Iowa.

The fact Thompson was able to work past that tough opening frame and get through 4 innings was an encouraging sign for the Cubs. He gave up another run in the 2nd inning when a leadoff walk came around to score but he was otherwise able to keep the Royals at bay.

Thompson finished with 73 pitches, allowing 5 hits and 2 walks. He struck out 1 and carries a 2.42 ERA in 28 big-league outings this season.

His first career MLB start came in a doubleheader against the Los Angeles Dodgers on May 4, right after he was initially promoted to the big leagues.

The Cubs utilized him out of the bullpen for the next few months until they opted to send him down to the minors to get stretched out for a run in the rotation. Thompson made 4 starts with Triple-A Iowa and didn’t allow a run over 14.2 innings.

“It’s not been too hard,” Thompson said of the build-up process. “Obviously it wasn’t fun to hear that I was going back down to Iowa to get stretched back out. But in the long run, I think it’s going to be the best thing for me.”

Six weeks remain in the regular season and the Cubs are currently deploying a six-man rotation. So Thompson and fellow rookie Justin Steele might have another 6 or 7 starts apiece down the stretch.

“I’m just looking for them to compete and continue to grow,” Ross said. “I don’t think there’s any real pressure on, ‘this is the one shot you get to be evaluated.’ These are moments to come up and prove yourself. They’ve proven that they can get outs in the big leagues and they’ve proven they’re really good in certain roles, coming out of the ‘pen.

“Now it’s just about establishing that you can do it over the course of 5, 6, 7 innings and going through a lineup multiple times, working in and out of jams. How you navigate that and compete throughout a game, I think that’s the thing that grows.”