Erik ten Hag was asked about the substitutions of Harry Maguire and Noussair Mazraoui following the conclusion of United's Premier League game against Aston Villa.
The defensive pair were both withdrawn at half-time at Villa Park, with Maguire in clear discomfort following a set-piece for the hosts in the closing stages of the first 45.
Noussair Mazraoui, like Maguire, also failed to reappear for the second period, with Victor Lindelof and Matthijs de Ligt sent on to fulfill the right-back and right-sided centre-half roles, respectively.
After the full-time whistle, manager Erik ten Hag was questioned about the pair, and confirmed that both were replaced due to physical issues.