CHICAGO -- If the White Sox had scored one more run in the eighth inning of their 6-1 loss to the Red Sox on Friday at Guaranteed Rate Field, then infielder José Rondón would never have made his pitching debut.

“Yeah, a grand slam,” White Sox manager Rick Renteria said. “If it was within a grand slam, that's my rule. That's what I was saying, if we would've scored one more run, we probably would've pushed [Carson] Fulmer to give us an inning. But since we didn't, it was Josey's job to do that.”

Rondon threw on the side prior to Friday’s game to get ready for a possible mound opportunity. The White Sox have nine relievers on their active roster, so a skeptic might ask why a position player would be needed in a still reasonably close contest.

• Box score

For openers, the White Sox have one off-day during the remainder of May on May 15. They also will be going with a glorified bullpen day Sunday even with Dylan Covey on the mound, so they need as many fresh arms as possible.

But the struggles of the starting rotation, a group whose ERA jumped to 6.40 over 30 games after Reynaldo López’s five-plus-inning effort against the Red Sox, has put unnecessary wear and tear on the bullpen. Jose Ruiz, Josh Osich and closer Alex Colomé, who had not worked since Monday, all followed Lopez. The rest was then up to Rondon.

“It felt good. It was fun,” Rondon said through interpreter Billy Russo. “Definitely something I'd be willing to do again.”

"That's as simple an explanation as we can make: just trying to save everybody that we could,” Renteria said. “Fortunately for us, Josey was able to do what he did, got us some outs.”

The final box score said Rondon threw 15 pitches and eight for strikes. Any information beyond that number might be tough to find, although it can be confirmed that two hits were allowed by the right-hander, and no runs crossed the plate.

There might have been a screwball in the mix, per Rondon. But the velocity and pitch type were so difficult to decipher that they rarely registered on Statcast. Rondon was trying to save his arm while trying to throw off the Boston hitters with his slower-than-a-knuckler sort of offerings.

"They just were laughing and stared at me like, 'You're really doing this?’” Rondon said of the reaction of Red Sox hitters.

Lopez, coming off a career-high 14 strikeouts Sunday against the Tigers, gave up six runs on eight hits over five-plus innings, including mammoth home runs to Rafael Devers in the first and Michael Chavis in the sixth. He fanned six, walked three and ended a stretch of three straight quality starts.

Chris Sale, one of the best pitchers in White Sox history, took another step to returning to All-Star form after a rough start to the current campaign by hurling six scoreless innings. He struck out 10, walked one and yielded three hits, excelling in the familiarity of Guaranteed Rate Field.

“It's never not going to be weird,” Sale said of his 119th career game pitched at Chicago's ballpark. “It's never not going to be something. Obviously, I pitched here it seems like a million times. I like this place. I've always liked pitching on this mound. Being here, it's special to me.”

Now, it’s also special to Rondon after his unique effort Friday.