Machado hurt his knee during an awkward swing Monday. His right leg simply collapsed under him and he eventually had to be helped off the field. Machado had surgery on his left knee during the offseason.
In 82 games this year, the 22-year-old Machado is hitting .278/.324/.431 (110 OPS+) with 14 doubles and 12 home runs. He missed the start of the season due to the offseason surgery.
The Orioles called up infielder Cord Phelps to replace Machado. Phelps is a .159 hitter in 53 big league games across the last three seasons.