The veteran centre halves have been at the club for several seasons, but are not first choice.
Even with Raphael Varane having left, United are likely to sign a new defender or two.
Per Fabrizio Romano, Maguire and Lindelof can leave if the right offer emerges, as he stated: "Even with De Ligt potentially joining, it's also a possibility for United to go for one more centre-back.
“It depends on the budget and opportunities but it’s a possibility. In terms of the future of players like Harry Maguire, Victor Lindelof and many others, it depends on proposals, if they receive good bids.
“But in general, one more center-back is a possibility – (Everton’s Jarrad) Branthwaite remains on the list but Man United have no plans to pay £70m, so the only way is if Everton’s price drops."