NEW YORK - Slumping center fielder Melky Cabrera was demoted to the minors Friday, the biggest move in a mini shakeup by the struggling New York Yankees as they tried to regroup for a playoff push.

The Yankees also designated backup first baseman Richie Sexson for assignment and placed pitcher Dan Giese on the disabled list. The club brought up three players from Triple-A Scranton/Wilkes-Barre: outfielder Brett Gardner, infielder Cody Ransom and reliever Chris Britton.

The speedy Gardner will get a chance to take over the everyday job in center field. He batted .153 with one extra-base hit in 59 at-bats for New York earlier this season, mostly as a fill-in while left fielder Johnny Damon was hurt.

Gardner was in the lineup Friday night, batting eighth and playing center for the opener of a three-game series against Kansas City.

A starting outfielder with the Yankees for most of the past three seasons, the 24-year-old Cabrera got off to strong start this year but has struggled at the plate since May.

He was batting .242 with eight homers, 36 RBIs and a paltry .296 on-base percentage, and his playing time had decreased lately.

“We just felt that it was time for him to go work on some things. You can't forget how young Melky is,” manager Joe Girardi said. “We believe that he's a much better player than a .240 hitter.”

Giese was put on the 15-day DL with rotator cuff tendinitis, the same injury Joba Chamberlain has.

After more than a week of rest and treatment, Chamberlain began a throwing program Friday. He made 25 tosses from 65 feet on flat ground and said everything went well. He plans to play catch again Saturday, but there is no timetable for his return to the mound.

“I want to pitch for a long time. I don't want to pitch for a year, so I understand I've got to be patient,” Chamberlain said.