Keys to the Yankees-Red Sox series

1. Pitch around Ortiz, V-Mart

In a Red Sox season dominated by injuries, there’s none bigger than the recent loss of Kevin Youkilis, who could be out for the season with a thumb injury.

Remember the days when the Red Sox had a lineup of relentless hitters one through nine, offering pitchers no break? Those are long gone. Now there are only three legitimate threats — David Ortiz, Victor Martinez and Adrian Beltre — so the Yankees’ pitchers can be selective in whom they go after.

With players such as Jed Lowrie, Bill Hall and Darnell McDonald getting regular time, there’s no reason why Ortiz or Martinez should be given pitches to drive, especially if there’s no one on base.

2. It’s on CC and A.J.

CC Sabathia has been surprisingly hittable since the All-Star break; opponents are batting .330 with a .400 on-base percentage during his last four starts. A.J. Burnett, meanwhile, is coming off a frustrating outing Monday in which he imploded during a seven-run fifth inning.

With fill-in Dustin Moseley pitching against Jon Lester on Monday, it becomes more important for the other starters to go deep into games. And with Sabathia and Burnett being paid to be the top two pitchers in the Yankees’ rotation, there’s no better time than this weekend for them to return to form.

3. Moving beyond 600

Alex Rodriguez admitted he was pressing during his chase for his 600th home run, which explains his 3-for-33 stretch leading up to the milestone homer. He looked quite relieved after Wednesday’s game, and now he has to carry that comfort level onto the field. Although he has driven in 87 runs and has done well with runners in scoring position (.293), his overall statistics are very un-A-Rod-like. Never before has he finished a full season with numbers close to his .334 on-base percentage and .473 slugging percentage. The eight weeks remaining on the schedule offer him enough time to change that.

4. Call to the bullpen

Joe Girardi insists he’s been using matchups to determine who pitches the innings leading up to Mariano Rivera. But it sure seems as if he is settling into a system in which Joba Chamberlain and David Robertson pitch the seventh and eighth innings, respectively.

With the atmosphere surrounding these games always ratcheted up, it will be interesting to see if Girardi follows this pattern or tries to work newcomer Kerry Wood into a big spot. And with Moseley’s start representing a big question mark, the manager might be inclined to be more aggressive with his late-inning bullpen strategy Sunday if the game is tight and a win is within reach.

5. Integrate the new pieces

With Lance Berkman and Austin Kearns now on the roster, Girardi has his work cut out for him juggling several people among the designated hitter spot.

For example, on days when Jorge Posada doesn’t catch, Girardi likes to use him as the DH to keep his bat in the lineup. How will that be affected by the need to get Berkman at least semi-regular at-bats?

These four games against a division rival should offer some insight into Girardi’s thinking.