Manchester United coach Michael Carrick admits there's uncertainty around the summer market.

Borussia Dortmund winger Jadon Sancho and Aston Villa playmaker Jack Grealish are just two of the targets expected to arrive at Old Trafford.

"Honestly, I'm not sure how that's going to work. I don't think it's been sorted," Carrick said.

“Contracts, for instance, how do they work? At every club, players' contracts are up; how do you sign players? I don't think it's been sorted.

"It's not something I'm directly involved in but we don't even know when we're officially going back to training yet.

"It's so much further down the line and it's a tough one to plan for. Then you start talking about: how much money is going to be left in the game to sign players?

"Not from us specifically, but from all the clubs, and how does that affect the whole transfer circus?"