NEW YORK -- Phil Hughes and his floundering fastball have been placed on the disabled list.

"We just feel like he's going through a dead-arm period," Yankees manager Joe Girardi said. "We don't feel that he's hurt."

Hughes is 0-1 with a 13.94 ERA through three starts this season. He was pulled with one out in the fifth inning on Thursday against the Orioles after allowing five runs on seven hits in the Yankees' 6-5 win in 10 innings.

Hughes' fastball has lacked velocity in 2011. He's throwing his fastball at an average of 89.3 mph this year, according to FanGraphs.com. His average fastball was 92.6 mph in 2010 and 93.8 in 2009, according to the website.

"My arm strength's not there," Hughes said Friday. "My arm feels dead."

Girardi said reliever Bartolo Colon will take Hughes' turn in the rotation. Colon allowed three hits and no runs in three innings of relief Thursday. It is unclear when Colon will make his first start, as the Yankees have two days off over the next seven days.

Hughes will remain with the team, throwing long-toss and conducting arm-strengthening exercises with pitching coach Larry Rothschild to try to work through the dead-arm issue. Girardi said Hughes will throw bullpen sessions when his arm strength returns. Hughes will also make at least one rehab start before he returns to the rotation.

The announcement Friday was a stunning and sudden setback for the 24-year-old right-hander, who earned an All-Star bid in 2010, finishing the season 18-8 with a 4.18 ERA. But he seemed to take the DL placement in stride.

"This will allow me to develop arm strength without having to worry about making my next start," Hughes said.

Hughes has allowed at least five runs and pitched fewer than five innings in each of his first three starts this season, just the third Yankees starter in the live ball era to do so. The others are Chien-Ming Wang in 2009 and Brian Boehringer in 1995.

Hughes has given up 16 runs on 19 hits in 10 1/3 innings in 2011. He's allowed four home runs and struck out just three batters.

"You can still get outs no matter what velocity you have but he wasn't getting outs," Girardi said. "He was struggling with getting outs and we were going to our bullpen early. It wasn't helping him, it wasn't helping us. So at that point we felt that we had to do something to help all parties."

Girardi was at a loss to explain Hughes' dead-arm issue. The manager said in the past that velocity wasn't an issue with his No. 3 starter. But the issue became hard to ignore after Hughes' velocity tailed off markedly after the second inning on Thursday.

"It's just not at the strength of where it needs to be to pitch seven competitive innings every fifth day," Girardi said.

In 2008 and 2009, Hughes' didn't have his peak fastball in early-season appearances, according to Girardi. But last season he was at peak velocity early on. It's worth noting that Hughes remained in extended spring training after the team broke camp and didn't make his first start until April 15 last year.

Said Girardi: "He's trying to figure out. ... He was on the same program he was the year before, he was doing the same stuff that he did, and it's just not coming out the same."

Girardi didn't rule out the possibility that Hughes' arm strength has been affected by the amount of innings he threw last season. The Yankees placed Hughes on a strict innings limit in 2010, skipping his starts periodically to keep his count down.

He finished with 176 1/3 innings pitched. His previous major league high was 86 innings pitched (2009).

"I don't think any of us have the exact answer," Girardi said.

He added: "We need to get him back to full strength."

Hughes missed nearly three months in the 2007 season with a strained hamstring he suffered in the seventh inning of a no-hit bid against the Rangers in his second major league start. He also spent time on the DL in 2008 with a strained oblique.

Skipping Hughes' next start was an option because the Yankees have two off days in the next week, but the team decided the DL was the best option.

"It's difficult to get through," Hughes said. "I didn't necessarily anticipate this. But it is what is and I have to adapt and try to figure this out."

The Yankees signed Kevin Millwood and Carlos Silva as insurance in case any of their starters -- No. 5 starter Freddy Garcia in particular -- faltered during the season. Millwood will make a start Sunday with Double-A Trenton. Silva reported to Tampa on Wednesday. It didn't sound like either was immediately available to make a major league start.

To fill Hughes' spot on the roster, the Yankees signed Triple-A reliever Lance Pendleton to a major league contract. Pendleton has made two relief appearances in Scranton, going 1-1 with a 1.59 ERA.

Ian Begley is a regular contributor to ESPNNewYork.com. ESPNNewYork.com's Mike Mazzeo contributed to this report.