Manchester United has made an official bid to acquire both Matthijs de Ligt and Noussair Mazraoui from Bayern Munich this summer.
The Athletic reports that the Old Trafford officials are eager to strengthen their squad by signing both defenders, submitting a combined bid on Thursday.
However, Bayern Munich has rejected the offer, anticipating a better proposal to finalize the deal.
With Aaron Wan-Bissaka expected to leave the club and the recent three-month injury to newly signed Leny Yoro, Manchester United is keen to enhance their wing-back and center-back positions before the season begins.