BOSTON - It's a slight alteration to the Phillies' pitching rotation: Roy Halladay and Kyle Kendrick will flip-flop spots, meaning Halladay starts Tuesday's series opener in New York against the Yankees and Kendrick pitches Wednesday.

But there are deeper reasons for the decision than just lining up Halladay to go against Yankees ace CC Sabathia in the Phillies' first game at Yankee Stadium since losing last year's Game 6 in the World Series.

By moving Halladay up one day (he still goes on regular rest because of Monday's off-day), the righthander will make six starts before the all-star break instead of five.

And Halladay's next start after Tuesday will come against the first-place team in the American League Central, the Minnesota Twins, instead of the last-place Cleveland Indians.

Dubee said that factor wasn't as important to him.

"I ain't worried about who we're getting him against," Dubee said. "I'm just getting him six starts instead of five."

For a team that has struggled to score for three weeks, more Halladay starts is a welcome idea. If there are no rainouts or injuries, Halladay will start against the Yankees, Twins, Blue Jays, Pirates, Braves and Reds before the all-star break. All but one of those starts will come on normal rest, with his start against Toronto (his former team) coming on six days' rest.

In 2010, Halladay is 8-4 with a 1.96 ERA. The Phillies have lost four of his last six starts.

Dubee said the team never considered skipping Kendrick altogether. Kendrick has pitched well as the Phillies' fifth starter, with a 4.95 ERA in 12 starts. But he is coming off his worst start in almost a month.

He will pitch against the Yankees with an extra day of rest.

"Some of our other guys have benefited from having a sixth day sometimes," Dubee said, citing Cole Hamels and Jamie Moyer.

Using the DH

Reserve Ross Gload started at designated hitter for Charlie Manuel on Friday, the first time the Phillies had use of the DH all season.

Manuel said he contemplated using first baseman Ryan Howard as the designated hitter but decided against it. Howard has played every inning of every game at first this season. It's possible, Manuel said, that Howard will get a day off from first in the coming days.

The Phillies' bench has struggled at the plate and the designated hitter could be a way to help some of the reserves.

Manuel said he chose Gload because he was 4 for 14 previously against Boston starter John Lackey. Gload, who entered the game with a .190 batting average in 42 at-bats, started for just the fifth time Friday.

"When you don't play," Manuel said, "it's hard."

Extra bases

Shortstop Jimmy Rollins (strained right calf) was scheduled to begin his official rehab assignment with single-A Clearwater on Monday but will instead begin Tuesday. A team official did not offer a reason for the delay. . . . Righthander Joe Blanton (1-4, 6.07 ERA) will make his eighth start of the season Saturday. Blanton's numbers over his first seven starts in 2009 were actually worse, with a 6.86 ERA. Blanton said he's usually not a slow starter and can't explain the last two seasons.