Yankees-Mariners Preview

Holding a comfortable lead atop the AL East was a luxury the New York Yankees were hoping to exploit in giving Joba Chamberlain an extended break. A number of close games have altered those plans.

Chamberlain will make his regular turn in the rotation Sunday when the surging Yankees attempt to sweep a four-game series from the Seattle Mariners at Safeco Field.

The Yankees (74-43) own the best record in baseball and are pulling away in the division race, holding a season-high 7 1/2-game advantage on second-place Boston.

The lead, which has been helped by a 12-1 stretch, has New York potentially cruising to the playoffs after failing to qualify last year.

With the Yankees comfortably ahead, they were hoping to rest Chamberlain (8-2, 3.85 ERA) until visiting Oakland on Wednesday in an effort to preserve the 23-year-old's arm following a pair of shaky starts.

The fiery right-hander is 1-0 while allowing eight runs and 11 hits with nine walks in 11 innings over his last two starts after going 4-0 with a 3.05 ERA in his previous seven.

"I'm just not trusting myself enough," Chamberlain said. "That's probably the biggest thing."

New York, though, has seen six of its last seven games decided by three runs or less, causing manager Joe Girardi to use his bullpen extensively and turn to his rising star earlier than he'd hoped.

"It is what it is. I understand the history and everything that's happened," Chamberlain said, referring to young phenoms such as Mark Prior whose careers have been derailed by injuries. "You've just got to be patient and try to learn.

"You want to continue to stay on your routine. It's like anybody who gets out of their own routine, it kind of throws them off a little bit. You just understand and be patient, and learn to adjust and make the most of it."

Chamberlain is expected to get his extended rest following Sunday's start until he likely pitches again nine days later, at home against Texas on Aug. 25.

The Yankees could use a strong effort from him as they attempt to complete a sweep of the Mariners (60-57) after Saturday's 5-2 victory.

Derek Jeter has been on a tear of late, hitting .478 with three homers and five RBIs over the last six games after getting two hits with one leaving Safeco and two RBIs on Saturday. That offensive surge has him tied with Omar Vizquel for second on the career list with 2,672 hits as a shortstop. The Yankees captain is one behind Luis Aparicio for the top spot.

Jeter has a .400 average with three homers and eight RBIs in his last 12 games at Seattle.

The Mariners have lost four of five, getting outscored 23-7 and batting .209 with one homer. They showed some improvement at the plate Saturday, getting 10 hits to equal their total from the first two games of this series.

Seattle will give the ball to rookie Doug Fister (0-0, 0.00), who is making his second start after allowing one hit in six innings before leaving to a standing ovation in Tuesday's 3-1 loss to Chicago.

"I was trying too hard to make the perfect pitch, instead of doing what I have been doing," Fister told the Mariners' official Web site of his four walks against the White Sox. "I have to re-evaluate what I was doing and go from there."

The 25-year-old right-hander went 6-4 with a 3.81 ERA in 22 games, including 17 starts for Triple-A Tacoma before being recalled Aug. 7, replacing the ineffective Jason Vargas.