Manchester United are prepared to pursue other targets if Everton are unwilling to negotiate over a fee for Jarrad Branthwaite, a source has told ESPN.
Branthwaite is a priority for United in the summer window, but Everton's valuation of more than £70 million ($89m) is problematic.
Sources have told ESPN that Branthwaite is keen to move to Old Trafford and contact with the 21-year-old's representatives has been positive.
United made an opening bid of £35m plus £8m in add-ons on Friday, which is set to be rejected. A source has told ESPN that Everton will need to compromise on their demands over a fee for a deal to happen.
Sources have told ESPN that United have other centre-backs targets including Marc Guéhi, Jean-Clair Todibo, Leny Yoro and Matthijs de Ligt and are prepared to move on if Everton refuse to negotiate.
According to a source, Everton will need to offload players this summer as they battle to stay on the right side of profit and sustainability regulations.
Everton, according to a source, are insisting their valuation of Branthwaite is fair and in part based on Josko Gvardiol's move from RB Leipzig to Manchester City last year.
Gvardiol, who is a similar age and also a left-footed centre-back, moved to the Etihad Stadium for a fee of around £77m.
United are working with a tight transfer budget this summer and sources have told ESPN that the fee paid for a centre-back will have a direct impact on which other targets can be pursued during the window.
The club are also looking to bring in a striker and a central midfielder with both top targets and lower cost options being considered.
United are hopeful of boasting their summer budget by securing permanent exits for Jadon Sancho and Mason Greenwood.
Both are valued at around £40m and United are keen to explore permanent deals first before considering whether to sanction loan moves. Sancho and Greenwood spent last season on loan at Borussia Dortmund and Getafe, respectively