The whittling of the Yankees Spring Training roster will continue, but for now, Karstens is keeping himself safe from a tap on the shoulder. The 24-year-old right-hander continued a stellar exhibition slate on Wednesday, throwing four innings of one-hit ball in a 4-1 win over the Twins.
Karstens has now reeled off nine shutout innings in Grapefruit League play, striking out nine and walking none, but he still intends to keep his profile low -- just in case Guidry sets out on another set of rounds.
"I'm just going to come in [Thursday] and do what I've been doing," Karstens said. "I'm going to sit in my corner and hide."
Chances are, Karstens doesn't need too low a profile. In fact, as surrounding lockers begin to clear out, Karstens' chances of making the Major League roster appear more realistic.
On Wednesday, the Yankees reassigned four pitchers -- Matt DeSalvo, Phil Hughes, Ross Ohlendorf and Karstens' spring roommate, Chase Wright -- to Minor League camp.
None were serious candidates to go north with the Yankees in April, but as starters begin to gain strength and log more innings, Karstens is making it difficult for the Yankees to look elsewhere.
"He's been doing the same thing every time out," manager Joe Torre said. "He's been that way from the first pitch he threw in Spring Training. He really doesn't waste any time. He works quickly and basically has kept the offense on the defensive."
Karstens feels that his fortunes have been on the rise since May, when he was demoted to Double-A Trenton after starting the season 0-5 in seven starts at Triple-A Columbus.
Karstens went 6-0 with a 2.31 ERA in 11 starts for Trenton before moving back up to Triple-A and continuing his dominance for Columbus, parlaying a 5-0 record and a 1.85 ERA across seven starts into his first Major League callup on Aug. 19.
"Just the way things have been going, it feels like they've been going up and up," Karstens said.
The San Diego, Calif., product admitted that he was slightly fatigued by the time he arrived in New York, having logged 147 2/3 Minor League innings to that point, but he still posted a 2-1 record with a 3.80 ERA in eight games (six starts).
That familiarity takes some of the shine off of Karstens' spring appearances, but they haven't dulled their value.
"We were aware of him before Spring Training started, because he helped us last year," Torre said. "It's not like he's surprising us. He's just continuing to impress us."
This spring, Karstens said he gained the courage to confer with a few of the Yankees' veteran pitchers on work-related topics. Andy Pettitte coached Karstens on keeping the same mindset from pregame bullpen sessions to the mound, and Mariano Rivera told Karstens to abandon a cut fastball that wasn't effective against Major League hitters.
When it comes to cutters, after all, Mo would know.
"You're so scared to talk to these guys, as a young guy in the clubhouse," Karstens said. "All you've got to do is ask and they're more than willing to give information out."
It's Karstens' goal to see to it that those words of wisdom don't go to waste.
"I'm trying to stay level-headed and relax," Karstens said. "I'm just going about my business. I don't say too much. I'd rather have what I do on the field speak for itself."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.