According to The Telegraph's James Ducker, United exercised a one-year extension option in Blind's contract to avoid losing him for free this summer, but unless they're willing to do so it will put a potential return to Ajax in jeopardy.
Blind came through the ranks at Ajax, and it has been reported the Eredivisie outfit want to bring him back to Amsterdam, per De Telegraaf (h/t Sport Witness):
However, the Dutch club do not have the resources to pay a fee to United, who spent £13.8 million on him in 2014, and match Blind's £120,000-per-week wages.
The player is believed to be receptive to the move, but unless he's prepared to accept a pay cut, the Red Devils may have to grease the wheels by lowering or even waiving a fee entirely.
Football writer Liam Canning believes the time has come to part ways with the 28-year-old:
Blind is good on the ball and a versatile operator. During his time at Old Trafford he has been used as a centre-back, a left-back and in midfield.
His lack of pace is a problem, though, and he only made 17 appearances in all competitions last term. While that was partially due to an injury that kept him out of action for 15 games, even when fit he was often left on the bench or out of the matchday squad entirely.
Samuel Luckhurst of the Manchester Evening News is no longer convinced by him in midfield either, as he noted during United's 2-1 defeat to Bristol City in the Carabao Cup last season:
Blind won four Eredivisie titles with Ajax prior to joining United and they're his hometown club, not to mention they'd likely be able to offer him a much more significant role than he currently enjoys with the Red Devils.
There's plenty of appeal for him in returning there, but much will depend on whether he's willing to take a drop in salary to do so.