MIAMI -- White Sox manager Pedro Grifol succinctly stated what his entire team and fan base felt following a 7-4 walk-off loss to the Marlins on Sunday afternoon at loanDepot park.

“These hurt; these hurt,” said Grifol after his crew matched a season-worst 40 games under .500 with its 26-66 record. “They’re all really tough. But these last two, they stuck me pretty good.”

Miami claimed a 4-3 victory Saturday after the White Sox had built up a 3-0 lead with ace Garrett Crochet on the mound. In Sunday’s series finale, the White Sox held a 4-1 lead after six innings and carried a 4-3 lead into the ninth with closer Michael Kopech (2-8) trying to finish off the series victory.

Kopech walked Vidal Bruján to open the ninth, and Bruján moved from first to third on Nick Fortes’ perfect sacrifice bunt up the first-base line with nobody covering third. Kopech retired Jazz Chisholm Jr. on a first-pitch fly out to left fielder Tommy Pham, but Josh Bell wouldn’t let him escape the jam, knocking a game-tying double just over Pham’s outstretched attempt.

After an intentional walk was issued to Jesús Sánchez, Jake Burger connected on a Statcast-projected 431-foot blast to left for a three-run game-winner. It’s the same Burger who hit 25 home runs for the White Sox in 2023 before being traded for Minor League left-handed pitcher Jake Eder. It’s the same Burger who rehabbed alongside Kopech when the right-hander was coming back from Tommy John surgery and Burger was working through a couple of left Achilles tendon tears.

“He’s a great hitter. We saw him over here for years. I’m excited for him, but it’s hard to be in the moment right now,” Kopech said. “For the most part, almost to most hitters in the league, I’m trying to go top rail. I’m not sure if I got it there. I haven’t looked at it. I don’t really want to look at it, to tell you the truth. It’s something I’ll assess tomorrow.”

“I was fortunate to get a pitch I could do something with,” Burger said. “[Kopech] is an awesome pitcher, and an awesome person. He has a fastball that can blow by you. You have to honor that. He and I spent a lot of time rehabbing together. It’s a cool moment, but that’s a good friend. I wish nothing but the best for the Sox the rest of the year.’’

Rookie Jonathan Cannon allowed one run over six innings and Danny Mendick homered for the first time since May 26 to help carry the White Sox advantage into the ninth. Cannon struck out three while walking four, throwing 49 of his 89 pitches for strikes. But the rookie minimized Miami’s damage with the help of nine groundouts.

Those good moments were erased by a four-run Miami ninth, beginning with a free pass and ending with a Burger blast. Kopech threw 18 four-seam fastballs and two cutters among his 20 pitches, with a potential overreliance on the four-seamer arising, despite the pitch averaging 98.7 mph and opposing hitters slugging .396 against it entering Sunday, according to Statcast.

“It’s coming down to what we talked about a lot lately in-house,” Kopech said. “I need to mix my pitches and not just rely on the fastball so much. It’s difficult to do that when I fall behind and my best pitch is my fastball. I have to get back in the count.”

“He does have to command the fastball,” Grifol said. “He’s not going to be able to pitch on secondaries alone, so he’s going to have to command the fastball. He’s going to have to use his secondary, and pitch. He’s got plus-plus stuff, but you’ve still got to pitch in this league.”

Sunday’s setback marked a 10th straight road series loss for the White Sox and Kopech’s fifth blown save.

“The ninth has been my role this year, and those situations I have a job to do, and I haven’t been doing it well,” Kopech said. “There’s no easy way to say that. It’s tough for me to say but it’s the truth. I’ve got work to do to get better.”