The decision means that Vazquez -- who is 1-3 with a 9.78 ERA in five starts this season -- will not be asked to pitch on Friday against the Red Sox at Fenway Park. Phil Hughes has been assigned to make that start instead, and he'll be followed by CC Sabathia and A.J. Burnett in the weekend set.
"He's struggling, so we've got to find a way to get him back on line," Yankees general manager Brian Cashman said of Vazquez. "It won't be easy; it probably won't be quick. He's going to do everything he can to get back on track.
"It will take some steps. It's not like it's going to be 'shazam' with a lights-out Javier Vazquez start that we saw last year. I think we'll build up to that."
After Vazquez was hammered on Saturday for five runs on seven hits -- including three home runs -- in three-plus innings against the White Sox, Yankees manager Joe Girardi said that the time was right to make a change, though Vazquez did say that he'd prefer to get back on the mound as soon as possible.
"He wants to get back out there and pitch, and that's how I would expect him to be," Girardi said. "I just thought he could use a little time to catch his breath.
"I know it's the Red Sox and everybody's going to think it's the Red Sox. But at some point, you've got to do something a little bit different."
Vazquez did not speak to reporters after the decision was announced on Monday.
In the time between starts, Vazquez is scheduled to throw a pair of side sessions. He skipped his normal mound time on Monday and will pitch bullpen sessions on Tuesday and Friday, which Girardi said would come with higher intensity than usual leading into his sixth start of 2010.
"Consistent location with consistent velocity would represent progress for me," Girardi said.
Girardi also said that the decision allowed the Yankees to offer Andy Pettitte an extra day of rest.
Vazquez was acquired from the Braves in a five-player December trade and had been slotted as the Yankees' No. 4 starter, but thus far, he has been the rotation's weakest link -- not the results the Yankees were hoping for as Vazquez attempts to erase memories of a poor second half in 2004.
"I believe that when you start to struggle, especially in a bigger market, you can be your own worst enemy because you want something so bad," Cashman said. "All of a sudden, you get on the wrong side of the mountain -- it's hard to stop. It's up to us to find ways to stop and regroup. That's what we're trying to do.
"When you're struggling like this in a market like this, it's louder and harder. He's not running from it. You can see that it bothers him. It hurts. He wants success, he wants to do right by everybody. He's fighting himself while he's doing it."
Girardi said that he has not been around Vazquez enough to make a definitive statement of the right-hander's mental state, but the manager said Vazquez's career numbers speak volumes. The righty was 15-10 with a 2.87 ERA last year for Atlanta, finishing fourth in the National League Cy Young Award voting.
"This is a guy that has pitched for a long time," Girardi said. "There could be some tough environments to pitch as an opposing pitcher. He went to Fenway last year and pitched a great game. He went to Philly last year and pitched a great game. Those are two pretty tough environments to pitch in. ... To do what he's done in his career, you have to assume that he's had to overcome things."
Girardi said that he believes Vazquez is healthy and noted that -- while his velocity has been a concern -- the club's radar readings saw him hit as high as 94 mph on Saturday against the White Sox. Cashman didn't seem as convinced.
"I worry that his velocity is down and I worry that his fastball command is not there," Cashman said. "Those are usually things where something's going on, but he said, 'No.' He said right now, he feels [health] is not the issue."
Girardi speculated that Vazquez's velocity fluctuations might be mentally related to his struggles, and he added that the right-hander's mechanical adjustments still need to be incorporated with his front shoulder, keeping his motion more over the pitching rubber.
"Some of the issues that we've had with the balls running back too far [over the plate], we've got to correct them," Girardi said. "We've tried his normal side sessions in between, and so far, we haven't had a lot of luck."
Vazquez was booed again at Yankee Stadium when Girardi took the ball from him after he faced four White Sox batters in the fourth inning, and Cashman acknowledged that the negative fan reaction won't make things any easier for Vazquez.
"They were behind him when [Saturday's game] started," Cashman said. "Our fans know he's fighting himself. Obviously, it's a results-oriented business, so we've got to find ways to do better. We all know he's clearly better than this, and he knows it, too.
"Hopefully, when the dust settles and the season's over, people are going to look at it and say, 'He went through some serious adversity, and he came out on top.' But it's going to take time."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.