Andy Pettitte feels good despite back

NEW YORK -- The Yankees are treating the back stiffness that affected Andy Pettitte in his last start as a one-time occurrence that should not impact his start Friday night in Boston or his ability to pitch in the playoffs.

That is, unless it happens again.

"Right now, we consider it a low-level red flag,'' GM Brian Cashman said. "If it happens again it will be a higher-level red flag. We'll find out Friday.''

As reported in the New York Daily News, Pettitte experienced the stiffness during his start against the Red Sox last Friday at Yankee Stadium, in which he allowed seven runs in 3-1/3 innings, by far his worst outing of the season.

Pettitte's next scheduled start would have been Wednesday night in Toronto, but after the Yankees clinched a playoff berth on Tuesday, he was moved back to Friday night to set him up for a likely Game 2 start next Thursday in the ALDS.

"If we hadn't clinched he would have made that start [Wednesday],'' Cashman said. "It stiffened up on him but he felt fine the next day.''

Cashman said no tests were performed or considered necessary, and likened the injury to the back spasms suffered last week by David Robertson rather than the disabling lower back problems that have kept Alfredo Aceves inactive since May. Pettitte underwent treatment and threw his regularly scheduled bullpen session this week, although Cashman said, "I suspect he may have cut back on some things.''

The 38-year-old left-hander was off to the best start of his 16-year career, amassing an 11-2 record and 2.38 ERA before going on the disabled list for two months with a groin strain suffered on July 18. The start against the Red Sox was his second one since returning to action -- he had pitched six innings of three-hit, one-run ball against the Orioles on Sept. 19 -- and after both starts said that he "felt great.''

Cashman said he had spoken to Pettitte on Thursday and gotten the same message.

"He said he feels good,'' the GM said. "But he's not pitching right now. We'll just see how he is after [Friday] night.''

Wallace Matthews covers the Yankees for ESPNNewYork.com. You can follow him on Twitter.