CHICAGO -- Trea Turner has seen a lot of baseball in his life, so he has seen plenty of pitchers react in plenty of ways to first-inning adversity.

He liked what he saw Tuesday night from rookie Michael Mercado.

“That’s what’s most important,” Turner said following a 6-4 victory over the Cubs at Wrigley Field. “To have that composure and compete and not get rattled by anything.”

Mercado made the first start of his MLB career on Tuesday, replacing injured right-hander Spencer Turnbull, who recently replaced injured right-hander Taijuan Walker. Mercado, who MLB Pipeline ranks as the Phillies' No. 30 prospect, threw a scoreless inning of relief in his MLB debut on June 24, but Tuesday was different, even if he said he felt the same nerves that he felt coming out of the bullpen last week.

“It’s one of those things that you dream about doing at a place so historic,” Mercado said about his start.

Mercado walked Michael Busch with one out in the first inning. He allowed a two-out single to Seiya Suzuki to put runners on first and second. He then fell behind Ian Happ, 2-0.

The game could have gone sideways fast, but Mercado kept calm.

“Throw it in the zone and see what happens,” he said.

Mercado evened the count before striking out Happ swinging on a 2-2 fastball to end the inning.

“That tells you a little bit about his makeup and his poise,” Phillies manager Rob Thomson said.

Mercado allowed two hits and one run in five innings. It has been almost 17 years since a Phillies pitcher allowed no more than two hits and one run in five-plus innings in his first MLB start. Fabio Castro did it on Aug. 23, 2007.

"He did a good enough job throwing strikes,” Cubs manager Craig Counsell said. “That was something maybe we had a chance at, I thought, facing him. But he did a good enough job throwing strikes. He got through the first inning. We had some good swings the first inning. We had good at-bats the first inning. We hit some balls hard the first inning.

"Once he got through that first inning, he did a nice job. We didn’t put pressure on them. We put pressure in the first inning and after that let them off pretty easy."

It helped that Turner had a big game, following his go-ahead single in the seventh inning of Sunday’s comeback victory over the Marlins at Citizens Bank Park. He hit a solo home run to left field in the third to give the Phillies a three-run lead, then smashed a two-run homer onto Waveland Avenue beyond the left-field bleachers in the fifth to give the Phillies a four-run lead.

“Left-center is pretty close here,” Turner said. “I spun them pretty good.”

It was Turner’s first multihomer game since Aug. 28, 2023, and the 15th of his career. He also singled to score a run in the seventh.

Turner is making his final push to start at shortstop for the National League in this month’s All-Star Game. He is tied with injured Dodgers shortstop Mookie Betts in MLB’s Phase 2 election to determine All-Star starters. Fans can vote until noon ET on Wednesday. The starters will be announced at 7 p.m. ET on ESPN. If Turner edges Betts, he will join first baseman Bryce Harper. He has already been elected a starter because he received more votes than any NL player. But Turner also is likely to join third baseman Alec Bohm, who has a significant lead over Padres third baseman Manny Machado in Phase 2 voting.

The Phillies haven’t had three infielders start an All-Star Game in the same year since Mike Schmidt, Pete Rose and Manny Trillo in 1982. They haven’t had a third baseman and shortstop start the All-Star Game in the same year since Scott Rolen and Jimmy Rollins in 2002.

“It would be cool,” Turner said. “Anytime you can get teammates together at the All-Star Game is really cool. I think for me personally, just the way I started last year, just to be in this situation is a win for me.”

Tuesday was a win for Mercado, who had a few baseball keepsakes tucked into a bag in the back of his locker. Maybe there will be more moments in the coming weeks.