CHICAGO -- The lesson for White Sox right-hander Gregory Santos, in crushing defeat, was quite simple.

“That I have to throw my slider,” Santos said through translator Billy Russo.

Santos has an impressive mix of pitches, including a sinker that averages 99 mph and a slider with good horizontal movement. As overwhelming as his high-octane velocity be, he would have thrown at least one more slider Wednesday night, if he had a do-over.

Santos gave up a walk-off three homer to Cubs slugger Christopher Morel in the ninth inning Wednesday, on a 99.5 mph sinker left over the middle of the plate. The blast gave the Cubs a 4-3 win over the White Sox. The Cubs entered the inning down 3-1 before rallying to win.

Santos acknowledged, in hindsight, he regretted the offering and would have gone to the slider.

“Yes, of course, because that’s my best pitch,” Santos said. “I had men on base, and I was trying to be fancy and that's what happened.”

Opponents entered Wednesday hitting .182 (22-for-121) against Santos’ slider this season, with only one extra-base hit, a double.

Of the 11 pitches he threw, seven were sliders, including two against Morel. Santos got him to chase one down and away on the second pitch of the sequence, to get ahead in the count 0-2.

He came back with another slider, one further away, and Morel didn’t bite. Now in a 1-2 count, he threw the sinker that Morel hit over the right-center field wall. It came after Santos issued a leadoff double to Cody Bellinger and a walk to Dansby Swanson.

“Attack the strike zone with him,” Santos said of his mindset against Morel. “I was ahead in the count and threw a good pitch. He didn’t swing at it. It’s like, ‘Well, let’s attack him again.’ It was a sinker, and he hit it.”

As much as Santos second-guessed himself, manager Pedro Grifol expressed confidence in both pitches after the loss. Whether Santos threw one or the other, it comes down to execution and conviction on the mound.

“I like both his pitches, so I’m not going to sit here and second guess which pitch he threw,” Grifol said. “I want him to throw the pitch that he has the most conviction in. That’s about it.

“In that type of environment, in that type of game, at the end, to get those last three outs, you’ve got to be convicted in every single pitch. If not, you need to step out and throw the pitch that you’re convicted on.”

That’s perhaps the larger lesson for Santos, who spoke before Wednesday’s game about his current opportunity to prove himself in the closer role.

Not only is he trying to cement himself as a closer for the rest of this season, but 2024 is a factor as well. He’s vying for a shot at the role next year, with Liam Hendriks expected to miss a large portion of the season recovering from Tommy John surgery.

“That's my goal, to show that I'm able to manage the role,” Santos said pregame. “Now I need to do my best and take advantage of it.”

Learning moments are part of the experience for a young pitcher, but wins and losses are what count most. Of course, there was more to Wednesday’s game than the ninth inning.

Gavin Sheets hit his first home run since June 16, a 419-foot, two-run blast in the fifth inning that gave the South Siders a 3-0 lead. It helped support Mike Clevinger’s dominant outing; he threw seven shutout innings -- his longest start this season.

Clevinger held the Cubs to three hits and two walks, striking out seven, in his fourth start since returning from a month-plus stint on the injured list. He had some extra life on his four-seam fastball, hitting 97.6 mph to strikeout Morel in the first. The pitch was averaging 94.1 mph this season entering the day.

“Anytime you throw at Wrigley, it has a little extra atmosphere,” Clevinger said. “The last time I pitched in this stadium was the 2016 World Series, so my juices were flowing, but I think it’s just finally being healthy.”

“He was electric,” Grifol said. “Velocity was up, pitches were sharp. He was crisp, got himself out of some trouble, made some great pitches, took us into the seventh inning with a 3-0 lead.”

The Sox had the bases loaded and nobody out in the eighth but didn’t score, striking out three straight times. Aaron Bummer gave up a solo homer to pinch-hitter Nick Madrigal in the bottom half of the frame, preceding the Cubs’ rally.

“It’s a tough loss, man,” Grifol said. “The toughest loss of the year, in my opinion.”