Bartolo Colon is congratulated by teammates after he pitched a...

Bartolo Colon is congratulated by teammates after he pitched a complete game shut out against the Oakland Athletics at Oakland-Alameda County Coliseum. (May 30, 2011) Credit: Getty/Ezra Shaw

ANAHEIM, Calif.

Here's a question no one at the start of spring training -- or the end, for that matter -- thought would be asked two months into the season:

Where would the Yankees be without Bartolo Colon?

"He's really exceeding our expectations and he's been huge for us," Mark Teixeira said. "If we didn't have him in our rotation, we'd be scrambling right now.''

Indeed, a guy in the running for Most Vulnerable Player at the start of spring training -- the 5-11, 265-pounder who hadn't pitched in two years, etc. -- is very much in contention for the more conventional long form of MVP (along with, of course, CC Sabathia, Curtis Granderson and Robinson Cano).

Colon, who pitched a four-hit shutout against the A's Monday, six days after he turned 38, is 3-3 with a 3.26 ERA. In 661/3 innings, he has allowed 58 hits, walked 15 and struck out 62. In eight starts, he has averaged just under seven innings and has a 3.11 ERA.

"For a guy to have that much life on the ball is just incredible," A's infielder Mark Ellis told the San Francisco Chronicle. "He knows what he's doing and he doesn't give in. The way he was locating was very impressive."

"It's Greg Maddux with power" was how general manager Brian Cashman described his thoughts while watching Colon and his corner-seeking, mid-90s fastball handcuff the A's.

The argument could be made that Colon and another oft-mocked signing, Freddy Garcia, 34, are the most significant reasons the Yankees enter Friday leading the AL East, two games ahead of Boston.

"I don't know where we're at without them, I really don't," Joe Girardi said. "They've both given us a chance to win almost every game that they've pitched. Their numbers are outstanding and they just continue to do what they've done. They've pitched at a very high level."

Said Alex Rodriguez, "They've been both saviors."

Garcia (4-4) has a 3.23 ERA in his nine starts, allowing 55 hits and 18 walks in 552/3 innings. His performance could be called surprising, but only moderately so. After all, he started 28 games last year with the White Sox, going 12-6 with a 4.64 ERA. He allowed three or fewer earned runs in 20 of those outings.

"Freddy when healthy," one AL scout said toward the end of spring training, "will figure out a way to get people out."

And Colon? "Anyone who says they saw this coming,'' a scout said this week, "is lying.''

Cashman didn't. "This was not expected," he said Thursday. "You take fliers on non-roster invitees. Most cases, they crash and burn. This has been something that's been huge for us."

Scouts Joe Caro and Bill Livesey recommended Colon, whom they saw pitch in the Dominican Winter League, to director of pro personnel Billy Eppler. Eppler reached out to Colon's winter league manager, who happened to be Yankees bench coach Tony Peña, who also recommended Colon.

But Cashman said, "What he's doing now, he wasn't doing in the Dominican. He's continued getting better and better."

Colon underwent treatment last year in which stem cells were extracted from the fat in his abdomen and bone marrow in his pelvis, run through a machine to concentrate the solution, then injected into his injured shoulder and elbow to promote healing, according to Dr. Joseph Purita, an orthopedic surgeon and member of a regenerative medicine clinic in Boca Raton, Fla. "This is no different than doing Tommy John surgery,'' Purita told Newsday's John Jeansonne recently. "Taking somebody's own tissue to rehabilitate an injury. All you're doing is transferring cells from one part of the body to another.''

It's Cashman's job to remain "uncomfortable" (his word), meaning he's fully aware that because of various injuries, Colon hasn't reached 100 innings since his AL Cy Young Award-winning 2005 season. He will be seeking pitching help as the trade market develops this month.

"I'm happy we're getting the production. It's certainly needed," he said. "It allows our kids [in the minors] to better develop on their time frame and for their needs. I hope this goes on the whole season but can't tell you it will. It's best for me to stay uncomfortable. I'll continue to keep my ears open on what's out there for possible reinforcements."