Outfielder Chris Dickerson has been called up from Triple-A Scranton/Wilkes-Barre to take Colon's spot on the team's 25-man roster.
Colon underwent an MRI at New York Presbyterian Hospital on Saturday night, but did not know the grade of the sprain. Manager Joe Girardi said the results of the MRI were "pretty good," but Colon will still need to be shut down for at least two weeks.
"I feel good, I just have a little bit of pain," Colon said through a translator. "I'm on the DL now, but I hope to be back after 15 days. ... After the 15 days, I should be back."
Colon will continue to work on other parts of his body, but doesn't know when he'll be able to start rehabbing his legs.
"I feel bad because the team needs help and I got hurt," Colon said. "But there's nothing I can do about it."
The 38-year-old suffered the injury while trying to cover first base and left Saturday afternoon's game with two outs in the seventh inning.
Colon (5-3, 3.10 ERA) ended up winning for the third straight start on Saturday afternoon, going 6 2/3 scoreless innings as the Yankees shut out the Cleveland Indians, 4-0, at Yankee Stadium. In his last 21 innings, Colon has surrendered just three earned runs.
Hector Noesi, who was summoned from Triple-A to replace Amauri Sanit (disabled list, elbow), could make Colon's next scheduled start on Thursday afternoon against the Texas Rangers, according to Girardi. The right-handed Noesi threw six innings of two-run ball out of the bullpen on Tuesday night against the Boston Red Sox before being sent down to the minors.
In four Triple-A starts, Noesi went 1-1 with a 3.92 ERA, allowing nine earned runs and 25 hits over 20 2/3 innings.
"I was a starter (in the minors) and it's normal for me to throw six, seven or eight innings," said Noesi, who was unaware that he might have to step into the rotation. "It's just (easier)."
Although he wouldn't commit to Noesi, Girardi said he's thrown 75 pitches and could conceivably give the Yankees 80-85 if need be. Other internal minor league options to take Colon's turn could be Adam Warren (4-2, 3.53), D.J. Mitchell (4-5, 3.04) or David Phelps (4-4, 2.95).
Colon lost out of the fifth spot in the Yankees' rotation coming out of spring training and began the season in the bullpen, but emerged out of nowhere with ace-like dominance after right-hander Phil Hughes was placed on the DL in mid-April with right shoulder inflammation.
Third baseman Alex Rodriguez called general manager Brian Cashman's free agent signing of Colon in February "the signing of the century."
"He's been consistently great all year. 1-A stuff," Rodriguez said Saturday.
Colon's loss couldn't come at a worse time for the Yankees, who are already dealing with a depleted bullpen due to the losses of Joba Chamberlain, Rafael Soriano, Pedro Feliciano and Damaso Marte due to various injuries.
Hughes is slated to make his first minor league rehab start on Tuesday for the Gulf Coast Yankees, but the Yankees don't know when he'll be back.
Colon's weight -- 265 pounds -- could be an issue as he begins rehab, but Girardi said "he's pretty quick for how big he is."
"I think you worry (more) about if a guy's favoring something that he could be hurting his arm," Girardi said.
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.
Mike Mazzeo is a regular contributor to ESPNNewYork.com. ESPNNewYork.com's Matt Ehalt contributed to this report.