CC Sabathia NEW YORK -- The most famous Yankee is Derek Jeter.

The most productive one is Robinson Cano.

The most reliable one is Mariano Rivera.

The most written-about one is Alex Rodriguez.

But the most important Yankee, to this team this year, is CC Sabathia.

"He's our No. 1," catcher Jorge Posada said Thursday after Sabathia dominated a putrid Oakland lineup to become the majors' first 19-game winner. "We follow him."

But what follows him in the starting rotation is a bit of a mess.

o And Ivan Nova, who is 23 and has made two big-league starts.

Think Andy Pettitte's simulated game Saturday to test his groin is a big deal?

Since the All-Star break, the Yankees have the AL's second-worst rotation ERA. In the second half, starters other than Sabathia have gone 15-14 with a 5.65 ERA and 226 hits allowed in 189 2/3 innings.

"He's been the one constant every time that he's went out," manager Joe Girardi said. "He's stabilized our rotation in a time where we've had some injuries and we've had some guys struggle. And that's what aces do."