At this point, neither Vazquez nor Buerhle knows whom manager Ozzie Guillen is planning to start in that Opening Day game against the Indians.
But if the two men look at these Cactus League outings as an audition, Vazquez made a strong case for Guillen to put his last name in the pitcher's slot that first game of the season.
Vazquez, 31, couldn't have pitched much better than he did against the Rockies. His performance was as smooth as an outing can be. He struck out seven, gave up one hit and allowed no runs in his first outing since his wife gave birth to the couple's second daughter on March 4.
He went back home to Puerto Rico to be there for her birth.
"I felt pretty good," he said. "I mixed my all my pitches, and that's something I didn't do as well my last time out."
Whatever problems he had in that earlier outing didn't display themselves in this one, because Vazquez dominated the Rockies from the start. He opened the first inning with strikeouts of Willy Taveras, Troy Tulowitzki and Garrett Atkins.
He had an uneventful second inning before allowing a leadoff triple to catcher Yorvit Torrealba, who got no farther than third. Vazquez struck out Chris Iannetta and Sean Barker and then retired Taveras to dash the threat.
No other Rockies reached base. Vazquez's performance was extraordinarily impressive, particularly to Guillen.
"I don't worry about Javy," Guillen said. "Javy and Buehrle, I wish I had guys like that with me, because they go about their business the right way. ... Those two guys, I don't worry about them."
It would easy to say why Guillen doesn't worry about his two aces. It might be hard for Guillen to decide which ace to pick: Buehrle or Vazquez.
"It's a great honor to pitch Opening Day," Vazquez said.
But pick Guillen must. He said he's two or three days away from making his decision, although it's not a big deal to Vazquez one way or the other. Neither is it for Guillen, who said he had no doubts about what Vazquez can do.
"I expect that from Javy," Guillen said after Vazquez pitched the White Sox to a 4-1 win over the Rockies. "I don't have any questions about Javy."