Left-handed reliever Stephen Tarpley was called up from Triple-A in his place.
Gardner has slashed .243/.325/.460 and has 15 home runs, 41 RBI and a .785 OPS. The 35-year-old is the longest-tenured Yankee on the roster, having joined the Bronx Bombers in 2008.
He last played on July 20 against the Colorado Rockies. Mike Tauchman has taken Gardner's place in the outfield, registering eight hits in 15 at-bats since Sunday.
Tarpley has a 6.59 ERA in 13 games this season, striking out 19 batters in 13.2 innings. He's had some control issues with seven walks during that span, but the southpaw's reentrance to a tired bullpen is a welcome sight after the Yankees used six relievers Tuesday against the Minnesota Twins before three more took the hill Wednesday.
The 66-35 Yankees somehow have the American League's best record even though they've suffered numerous injuries among the lineup and pitching staff. The outfield in particular has experienced terrible luck in this regard, with Gardner, Aaron Judge, Giancarlo Stanton, Aaron Hicks and Cameron Maybin all hitting the IL at some point this season.
The Yankees' depth has shined, though, with players such as Tauchman and Clint Frazier excelling in place of the starters.
For now, Gardner will miss the entirety of the Yankees' four-game series at Fenway Park against Boston Red Sox, which begins Thursday. He'll also sit out New York's two-game home series versus the Arizona Diamondbacks. He'll be eligible to return during his team's four-game home set against the Red Sox in early August.