Manchester United are increasingly confident of signing Antoine Griezmann from Atletico Madrid in the summer - for what could be another world-record fee - although Luke Shaw is almost certain to be on his way out of Old Trafford at the same time, with Jose Mourinho frustrated at the left-back's lack of development.

Intermediaries representing Griezmann and United have been talking for several months, and the Euro 2016 top scorer is said to be extremely keen on the move, with the chance to link up with international teammate Paul Pogba only making it more enticing. The principles of any prospective deal have already been verbally agreed, including weekly wage and prospective shirt number.

United would likely have to match Griezmann's buy-out clause, that is set at €100m. Complicating the transfer, however, is that Atletico are currently serving a transfer ban and are still waiting on the Court of Arbitration for Sport to decide on whether they will be able to buy and sell players this summer.

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If they are, Atletico will revive their interest in Diego Costa - as reported by The Independent on Monday - as a potential replacement for Griezmann.

United will meanwhile be open to offers for Shaw. The 21-year-old has only made 13 appearances for the club this season, with none in the league since 29 October and none in any competition since the 30 November League Cup win over West Ham United.

Manchester United's potential summer transfers Show all 6 1 /6 Manchester United's potential summer transfers Manchester United's potential summer transfers <b>In:</b> Victor Lindelof United have been linked with signing the Benfica centre-back for some time now. Rumours have however surfaced that the Red Devils might be deterred at the fact that the Swede has signed a new contract which will increase his release clause to a reported £50m. Manchester United's potential summer transfers <b>In:</b> Virgil van Dijk The Southampton central defender was subject to a lot of interest from the league’s big clubs approaching the January transfer window. Many clubs will likely return for him when the window reopens. Manchester United's potential summer transfers <b>In:</b> Antoine Griezmann One of the world’s most sought-after talents, United would have to pay big money to bring him to Old Trafford. With Zlatan Ibrahimovic coming to the end of his career, Griezmann could be seen as a long-term choice to spearhead United’s attack. Atletico’s main man won Player of the Tournament at Euro 2016, after scoring six goals. Manchester United's potential summer transfers <b>In:</b> James Rodriguez The Colombian international has spent most of this season on the sidelines, with most of his appearances coming from off the bench. Despite this, it would still require a high fee for Real Madrid to let him go after they signed him from Monaco for £63m. Manchester United's potential summer transfers <b>In:</b> Yannick Ferreira-Carrasco This campaign, United have failed to have a consistent performer in the left-wing role with Memphis Depay and Jesse Lingard flattering to deceive for the most part. Carrasco would be a perfect fit, slotting in alongside Ibrahimovic and Henrikh Mkhitaryan in their front three. They’d have to break the bank to prise the 23-year-old away from the Vicente Calderon, though. Manchester United's potential summer transfers <b>In:</b> Nelson Semedo United have been heavily linked with Semedo’s teammate Lindelof, but reports suggest that Mourinho is interested in the right-back also.

Mourinho is said to have become frustrated with Shaw's lack of progress in what the manager is trying to do with the team, and that has even led to some senior first-team players speaking to the young defender privately.

Jose Mourinho is frustrated with Luke Shaw's lack of development at Old Trafford (Getty)

United will listen to offers in the summer, with Chelsea and Tottenham Hotspur - depending on Danny Rose's future - earmarked as potential buyers, although it remains to be seen whether United would sell to a rival.

Shaw has not yet been completely written off, and could yet turn his situation around, but those close to the squad say he has a lot of convincing to do.