Both were first-round draft picks, Kershaw by the Dodgers in 2006 and Wacha by the St. Louis Cardinals six years later. Both played high school baseball in Dallas, both pitched in the postseason as rookies and both have been unhittable at times.
But the most important similarity is the fact both will be on the mound for Game 6 of the National League Championship Series on Friday. And given their common backgrounds, the unflappable Kershaw predicted there's one other trait Wacha figures to share with him Friday.
"I don't think nerves are going to be an issue for him," he said.
They haven't been so far. In two playoff starts — both wins — Wacha has given up a run and six hits in 14 innings. In the first of those, against the Pittsburgh Pirates in the division series, he came within five outs of a no-hitter. In the second he outdueled Kershaw, holding the Dodgers scoreless for 6 2/3 innings.
So much for postseason pressure.
"There are some guys who have been able to embrace that and use that to their advantage. I think Michael's one of those," his manager, Mike Matheny, said.
Maybe that comes from another thing Wacha shares with Kershaw: enormous confidence.
"If you have doubts in your mind that you're not going to be a good pitcher in the postseason, you're not going to do any good out there," Wacha said. "So you try to think that you're going to have a spot on this rotation for the postseason and prepare yourself for that."
Even when you're in the minor leagues, which is where Wacha was in August? Or when you're pitching against college teams, which Wacha was doing 16 months ago?
"Even back [then] you've got to think about being a good pitcher in the postseason and set your expectations high," he said. "And my expectation in spring training was to be up with the big club and help them win the World Series.
"We haven't met those expectations yet."
Of course, the big-budget, star-studded Dodgers had those same Texas-sized expectations. But Friday there can be just one lone star: either Wacha, who can pitch the Cardinals into the Series with a victory, or Kershaw, who can force a decisive Game 7 if he wins.
Neither pitcher fits the mold of the typical Texas gunslinger, a stereotype popularized by such cocky hard-throwers as Nolan Ryan, Roger Clemens and Josh Beckett. Although Wacha and Kershaw both have fastballs that can reach the mid-90s, they succeed by keeping opponents off-balance — Kershaw with a funky delivery and a devastating curveball and Wacha by mixing speeds and throwing an excellent changeup.
And unlike the boastful Beckett and the brash Clemens, Kershaw and Wacha are quiet and mature beyond their years.
There are differences. With his two victories this month, Wacha, a 22-year-old right-hander, already has more postseason wins than Kershaw, a 25-year-old left-hander who is 1-2 in four postseason series.
"You learn from experience," said Kershaw, who has won 77 big league games in six seasons and will probably claim his second Cy Young Award next month. "The first couple times in the postseason, I didn't pitch as well as I would have liked. I don't know if people can say it's because of nerves or whatever, but maybe I just didn't pitch that well."
He's pitching better now. In three playoff starts this year he has given up one earned run in 19 innings, striking out 23. He has only won once, though, losing to Wacha in Game 2 despite holding the Cardinals to two hits and an unearned run.
Still, you'd be hard-pressed to tell the veteran from the rookie — and maybe that's because of the circumstances. Kershaw, who is pitching to extend his team's season at least a day, goes about his work serious and unsmiling.
Wacha, who is pitching to send his team to the World Series, wears a permanent grin and answers questions with cliches — most of which begin reflexively with the words "I mean."
"It's the fun time of the season," Wacha said with a grin. "My job is just to go out there and try to win a ballgame. And that's the plan going into it."