The options are clear: Mark Buehrle, whose eighth career Opening Day start would break a tie with Billy Pierce and set a new franchise record, and Jake Peavy, the definition of a staff ace.
Let the discussion begin with comments from Peavy, who after just 5 1/2 months seems as comfortable in his environs as if he'd been part of the White Sox organization for the past decade.
"I was excited about being a part of this staff, but this is Mark Buehrle's staff, and I've said that all along," said Peavy during Friday's pre-SoxFest media get-together. "He's been here for nine or 10 years. This start would be monumental for him, and I would love to see that happen.
"Mark is a buddy. I like to see buddies accomplish different feats."
Peavy, 28, and Buehrle, 30, have a far greater difference in pitching styles than simply one throwing right-handed and the other being a southpaw. Peavy can throw his fastball with velocity in the mid-90s, whereas if Buehrle hit 95 mph, that particular speed gun probably would be re-examined for accuracy.
Both pitchers have great movement on their pitches, with Buehrle relying a bit more on pinpoint location. But their mound demeanor also is slightly different.
"Just watch them pitch," said White Sox starter John Danks with a laugh when asked to explain the difference between the two. "Jake is kind of scary when he's on the mound. They both have their own styles, but they know what they are doing and know how to win ballgames."
Assistant GM Rick Hahn told the story this past week of being present at Peavy's first injury rehab start for Triple-A Charlotte last season. Peavy was grumbling at the home-plate umpire in the first inning over perceived calls, according to Hahn, and that illustrates Peavy's burning desire to win -- something he almost wills on everyone behind him when he pitches.
Meanwhile, Buehrle was the guy joking with teammates as his start on July 23 against Tampa Bay drew closer to the second perfect game in White Sox history. It's hard to go wrong either way when thinking of an Opening Day hurler.
"You know what it is? It is Ace 1 and Ace 1A," said Danks of Buehrle and Peavy, who have a combined career record of 230-165. "It doesn't get much better than that."
Peavy's right ankle and right elbow, which took a direct hit off a line drive during a rehab effort last year, were pronounced "as healthy as can be" by Peavy. Buehrle's sore left shoulder has benefited from offseason arm work, although he said he won't know the true value of his efforts until he witnesses the second-half response.
Let's go back to that Opening Day question, though. How does Buehrle feel about relinquishing the chance at the record to Peavy in his first full year with the White Sox?
"To be honest, I don't care if I'm No. 1 or No. 5," Buehrle said. "I just want to go out there and pitch every five days. If I'm not the Opening Day starter, I'll sit back and enjoy the festivities and get ready for whatever they give [the ball] to me.
"Once we acquired Peavy, how do you not pitch him Opening Day or as much as you can? The guy is a stud, and I think he makes this team better."
That franchise record plays a little in Buehrle's mind, but he quickly added that it won't be a source of consternation after he retires if that eighth Opening Day start never arrives. The final say in the matter belongs to Guillen and pitching coach Don Cooper.
Though they certainly want to protect Buehrle's first-half workload, something possibly facilitated by starting him in the rotation's four slot, there's a good chance Buehrle will get his chance to set that Opening Day mark. The bottom line is that any of the five White Sox starters have the Opening Day pedigree, which is a good problem to have.
"If I go with my heart, then I pick Buehrle. If I go with my brains, then it's Peavy," Guillen said. "I talked about it with Kenny, but we don't have a decision yet.
"Buehrle is pretty good early in the season, and I think he does a lot of things for our organization. He has earned that respect. Whatever decision we make, it will be tough."