Marcos Rojo limped off Manchester United’s UEFA Europa League quarterfinal second leg against Anderlecht on Thursday.
The 27-year-old Argentine tried to continue but could hardly run en route to a 23rd minute exit from the Old Trafford pitch.
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United plays Sunday against Burnley, and is already missing Chris Smalling and Phil Jones from its center back corps.
Daley Blind replaced Rojo alongside Eric Bailly. United’s bench was already attack and midfield heavy, with Marouane Fellaini, Wayne Rooney, Anthony Martial, Ashley Young, and Ander Herrera available.
Youngsters Axel Tuanzebe and Timothy Fosu-Mensah finish off United’s defender depth on the roster if Rojo is gone for any period of time.