Manchester United manager Jose Mourinho has lost patience with Chris Smalling and is ready to listen to offers for the England international, according to reports.
Smalling, 27, has dropped below Phil Jones, Marcos Rojo and Eric Bailly in the pecking order at United, although he could start alongside Daley Blind in central defence in the Red Devils' Europa League final showdown with Ajax on 24 May.
Mourinho has previously criticised Smalling and Jones for being "cautious" in their recoveries from injury, at a time when United were short of fit centre-backs.
But the Portuguese manager has insisted the English pair have a future under him.
"It's not just about them. It's about the philosophy and mentality around them. Cautious. Cautious. Cautious. Just a cautious approach," Mourinho was quoted as saying by Sky Sports.
"It's a profile, it's the philosophy of work. Just that."
United have been linked with summer moves for Burnley defender Michael Keane – who is a product of the Red Devils' academy – as well as Benfica centre-back Victor Lindelof.
The Old Trafford outfit are expected to make a formal bid for Keane following the Europa League final, with Burnley expected to demand around £30m ($39m) for a player they signed from for £2m United in 2015.
A 25% sell-on clause was included in the deal that took Keane to Turf Moor, meaning United will effectively get a discount if they buy him back in the summer.
Burnley boss Sean Dyche said the Clarets were in a "strong position" over Keane, despite the centre-back only having a year left on his deal.
"He's got a year to run on his contract, and if nothing happens that is suitable for us, the situation will go on and he'll carry on playing," he was reported as saying by ESPN.
"We'll wait and see what the summer brings."