San Francisco's Tim Hudson has the lowest ERA in the majors.
Chris Sale would lead the AL in that category had he not missed more than a month with an injury.
Two of the majors' top pitchers square off on Chicago's south side as the NL West-leading Giants look to snap a season-high four-game skid Wednesday against the White Sox.
Hudson (7-2, 1.81 ERA), who turns 39 next month, has been the star of the Giants rotation during the first 2 1/2 months of his San Francisco tenure. The right-hander has not yielded an earned run in three of his last four starts, going 3-0 with a 1.04 ERA.
His stellar start has come after he missed the final two months for Atlanta last season with a broken right ankle.
"I've always admired him from the other side, how well he competes," manager Bruce Bochy said. "I felt we were getting a front-line pitcher who will give us a chance to win on a consistent basis. He's done all we've expected and even more."
Hudson was on the mound for the Giants' only victory in their last eight games, allowing an unearned run in seven innings of a 7-1 win over Washington on Thursday. San Francisco (43-28) has since dropped four in a row while yielding 28 runs.
"I just try to go out there and give us a chance to win," Hudson said. "It doesn't matter that we lost three in a row or won three in a row. I feel like I put forth the same effort every time."
In the outing prior to suffering his season-ending injury July 24, Hudson beat the White Sox as he allowed four runs in 7 1-3 innings of a 6-4 victory at U.S. Cellular Field. His 9.00 ERA in five career starts there is his worst in any ballpark.
Sale (5-1, 1.97) has not pitched enough innings - 59 1-3 - to qualify to be among the ERA leaders but would rank third in baseball behind Hudson and Cincinnati's Johnny Cueto. Sale is 2-1 with a 1.69 ERA in five starts since returning from a flexor muscle injury.
The left-hander, who has never faced the Giants, plans to focus on himself and not Hudson.
"I try not to put too much emphasis on who I'm facing," Sale told the White Sox's official website, "but obviously (Hudson's) body of work over his career, especially over this past year and coming back from a big injury like that (makes him) really just being one of the most dominant pitchers in the game."
Sale was outdueled by reigning AL Cy Young Award winner Max Scherzer on Thursday, yielding one run and tying a season high with 10 strikeouts in seven innings of a 4-1 loss to Detroit. He gave up a homer for the third straight game after allowing one through his first six.
He's been brilliant in his last five home starts, surrendering three runs and nine hits in 32 innings with 43 strikeouts and four walks.
Gordon Beckham and Dayan Viciedo each hit two-run homers as Chicago (34-37) snapped a four-game slide with an 8-2 victory Tuesday. The White Sox have won four in a row versus San Francisco, which suffered its first defeat in seven interleague games this season.
Chicago's Adam Eaton is batting .400 in his last nine games and .355 in his last eight against the Giants.
Michael Morse is one of two Giants to have faced Sale, going 1 for 4 with a homer and three strikeouts. Gregor Blanco is 1 for 2 against him.