Not a great week if you're New York Yankees general manager Brian Cashman.
Colon, Cashman's prized free agent find of 2011, was removed from his start against the Cleveland Indians on Saturday with a strained left hamstring.
He was undergoing an MRI at New York Presbyterian Hospital on Saturday evening to determine the extent of the injury. Results were unavailable.
Joe Girardi said after the game -- a 4-0 Yankees win -- that the team would likely call up a minor league pitcher to replace Colon if the veteran right-hander misses his next start.
One candidate is reliever Hector Noesi, who allowed two runs in six innings of relief against the Red Sox on Tuesday before being sent to Triple-A Scranton the next day.
Cashman confirmed on Saturday night that Noesi will be called up on Sunday to replace Amauri Sanit, who has a shoulder injury. But the Yankees could conceivably call up another reliever and have Noesi make the start.
"Your hope is you have enough depth to cover everything but you're asking young guys (to do) a lot," Girardi said.
Colon was removed with two outs in the seventh inning on Saturday. He pulled his hamstring while running over to first on a Shin-Soo Choo groundball fielded by first baseman Mark Teixeira. He received the throw from Teixeira to get the out but came up lame.
Colon, who was not available for comment after the game, had allowed just two hits and struck out six on Saturday while holding the Indians scoreless through 6 2/3 innings.
The 38-year-old had allowed just three earned runs in his last 21 innings.
While lamenting the injury, Alex Rodriguez said Colon was pitching with the same repertoire that he flashed in 2005, the season he won the American League Cy Young Award.
"He's been consistently great all year. 1-A stuff," said Rodriguez, who referred to Colon's February addition to the Yankees as "the signing of the year."
On the season, Colon is 4-3 with a 3.39 ERA.
The Yankees have relied on the veteran to fill in for Phil Hughes, who was placed on the disabled list in April with a shoulder injury and was largely ineffective in his three starts in 2011.
In addition to Hughes' injury, the Yankees have suffered significant losses in the bullpen.
Chamberlain will be sidelined for the next 10 to 14 months due to a torn elbow ligament. Right-handed setup man Rafael Soriano's return from an elbow injury is indefinite. Left-handed specialist Pedro Feliciano has just started playing catch with the hope that he can fully recover from a left rotator cuff strain.
Just how long Colon will be out is unknown, though his lack of conditioning (he is listed at 265 pounds) will likely present a challenge in his rehabilitation.
Colon's success with the Yankees this season comes on the heels of an unorthodox offseason shoulder surgery that involved stem cells being injected into his painful shoulder and elbow. The doctor who performed the surgery has given HGH to other patients, though he claims that he did not give it to Colon. The surgery is being investigated by Major League Baseball.
Ian Begley is a regular contributor to ESPNNewYork.com.