Harry Maguire was dropped by Ralf Rangnick for Manchester United's Premier League clash with Watford on Saturday.
The England international was one of four changes from the Champions League draw with Atletico Madrid in midweek.
He, Luke Shaw, Marcus Rashford and Jadon Sancho all dropped to the bench.
Alex Telles, Aaron Wan-Bissaka, Nemanja Matic and Anthony Elanga were the four players who came in.
The decision to leave out captain Maguire - still the world’s most expensive defender - was eye-catching given the recent questions over his influence as club captain and his indifferent form.
Rangnick has backed his captain publicly, despite suggestions that he isn’t overly fussed by claims that the England defender is feeling the strain of United’s inconsistent campaign.
Interim boss Rangnick has called on Cristiano Ronaldo to mentor the young players within the squad, which is understood to have led to further friction with Maguire.
And sources close to Maguire told Mirror Football this month: “That’s left Harry in no man’s land, as he’s the captain and having to say and follow whatever Ronaldo says, to keep everything sweet.”
Maguire hasn’t been at his best in recent months on the field.
Maguire was at fault for Joao Felix’s early goal in midweek, unaware of the Portuguese internationals movement across him - while also not getting a shout from Shaw.
The lack of communication between the pair has been highlighted on numerous occasions this season and has cost United goals in a number of big games - notably the home defeat to Manchester City towards the end of Ole Gunnar Solskjaer's reign.
Despite the duo's familiarity with one another - playing together as left-sided centre-back and left-back for both club and country regularly in the past two years - it has been a cause for consternation at Old Trafford.
Rangnick insisted to MUTV that the decision to make all four changes was purely down to rotation.
“It’s our third game in six days, we only came back very late [in midweek] so it’s about fresh people, fresh legs, fresh energy and some things we need tactically against this team," he remarked.
But it's understood he is increasingly keen to take a more detailed look at a central defensive partnership of Victor Lindelof and Raphael Varane, with the Frenchman back from injury and the Swede having impressed in recent weeks.
Bruno Fernandes took the armband in Maguire's absence.
