WASHINGTON (AP)—The top-ranked doubles team of American twins Bob and Mike Bryan have pulled out of next week's Citi Open, citing an injury to Bob's shoulder.

Tournament officials announced the withdrawal Friday.

The Bryans haven't played since July 6 at Wimbledon, where they became the first men's doubles team in the Open era to win four consecutive Grand Slam titles.

The brothers own a record 15 major championships in all.