Paul Pogba is likely to leave Manchester United this summer with Real Madrid and Juventus both chasing the midfielder, according to Sky in Germany.
The 26-year-old France midfielder would prefer to join Zinedine Zidane's side in Spain, per the same source.
United want to keep Pogba at least until the end of the season due to a lack of replacements available on the market in January.
But a summer deal will be difficult to conclude for any club, with United understood to want a fee in the region of £150m for the World Cup winner.
There is also a complex relationship between the club and Pogba's agent Mino Raiola, who brought him back to Old Trafford from Juve in 2016.
The player, who was a United youth graduate, also signed a five-year contract when he rejoined that contains the option to extend it by a further year until 2022.
Pogba said last summer that he was thinking of leaving the club for "a new challenge" and Raiola also said "everyone knows the willingness of Paul to move on" - but a transfer did not materialise.
Any deal for the figures United are understood to want will be hindered by Pogba's lack of appearances. He is presently recovering from an ankle operation and will not be back until after the winter break.
So far this season the midfielder has made just eight appearances in all competitions - six at the start of the campaign and two more in December after a 10-week lay-off due to an ankle problem.
James Cooper, Sky Sports News north west reporter
The most interesting part of this talk is the timing of it. Here we are in the January window where Paul Pogba is not going to go anywhere, he is not going to leave Manchester United - he's not even been playing for Manchester United.
Ole Gunnar Solskjaer told us on Tuesday, funnily enough, that Pogba won't play ahead of the winter break for Manchester United which is around about February 8/9 so we are looking at mid to even late February for him to make his return.
What will be really interesting now - this is all about the game after the transfer window. We know that Pogba is passionate about playing for France. He will want to play for France in the European Championships. To do that he will have to return for United as well.
There are problems with trying to do a deal as well - United want about £150m for a player who has hardly played this season and I think he'd expect his wages to be a little higher than they are here and they are pretty handsome at Old Trafford, I can tell you that.
Then you look at the timing of this - Paul Pogba's agent is the same agent who didn't manage to bring Erling Haaland to United a few weeks ago. There are slight moments of tension there and a lot of United fans will think 'here we go again' and, for us, as soon as that transfer window closes on January 31 at 11pm the drums will start beating on Paul Pogba for the summer.
What do the fans think?
It is a very difficult one - you have to look at the history of Paul Pogba and Manchester United to understand how United fans feel about him.
He grew up through the academy then left, rather publicly falling out with Sir Alex Ferguson, who was irritated with the manner in which Paul Pogba decided to go to Juventus and that was difficult. Bringing him back, I think there was fanfare about breaking the transfer record and United were quite rightly very pleased about that and there have been flashes of brilliance.
Manchester United fans know that Pogba is probably the most talented player in that squad and Solskjaer certainly knows that having brought him through the academy and watched him leave for Juventus. They just haven't seen enough of those flashes of brilliance.
And here we go again, Paul Pogba, or somebody associated to Paul Pogba, talking about leaving and wanting to go to either Real Madrid or Juventus.
I think a lot of Manchester United fans have finally had enough.
This term he has played six games in a chunk at the start of the season then a 10-week gap and then two games and United have spluttered without him. On the pitch he represents something far better than some of the players who have come in in his absence so you can see all those frustrations.
United fans will want to see their club get a big fee for Pogba if he is allowed to leave but he has a year-and-a-half on his deal - he signed a five-year contract back in 2016 - there is an option on that of another year so, effectively, Manchester United have two-and-a-half years of Pogba.
This one will rumble on and on but it is really sad when you know there is such a good player in there, somebody who is very interesting to talk to and who works hard for Manchester United, but that there won't be too many people who are sad to see him go if that does happen this summer.
How to follow the January transfer window with Sky Sports
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
Start your day with Good Morning Transfers at 9am as our team of reporters bring you the latest news and insight. Transfer Talk then follows at midday delivering analysis of the biggest stories. Then join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
Meanwhile, the Transfer Talk podcast will also be back at the turn of the year with more expert analysis from here and across the continent.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.