How high is Zach McAllister’s ceiling?

In 2006, the Yankees thought enough of McAllister to take him in the third round of the draft, but his stock obviously fell precipitously, because General Manager Chris Antonetti was able to make him an Indian in 2010 for the bargain basement price of Austin Kearns.

McAllister’s 3-3 record is not an accurate indicator of how well he has pitched, but his 2.63 ERA is. He manhandled the Athletics Tuesday night, throwing 7⅔ shutout innings, giving up five hits and one walk.

One of the weapons he employed is new.

“We talked to him all spring about throwing a splitter,” manager Terry Francona said Wednesday. “We felt like he has the perfect arm slot to do it, and he was scuffling with his breaking ball. He tried the splitter in the bullpen and fell in love with it.”

Falling in love with a pitch can be dangerous. Some pitchers will throw the same pitch continuously until they are back in the dugout wondering how they gave up 14 runs in three innings.

“We reminded Zach not to become Bruce Sutter,” Francona said. “A lot of you probably don’t know who he is. But we don’t want Zach to become a soft-throwing right-hander.”

Sutter, who pitched in the 1970s and ’80s, was among the first, if not the first, pitcher to throw a split finger fastball. He threw it almost to the exclusion of every other kind of pitch, but Sutter was a hall of fame reliever, so he is the exception to the rule.

McAllister unveiled his splitter on April 24 against the White Sox at U.S. Cellular Field.

“[Alejandro] De Aza was the leadoff hitter, and on the second pitch, McAllister threw a splitter,” Francona said. “He’s a confident kid.”