Alejando Garnacho's agents and Manchester United are at odds over new contract talks.
The Sun says United want to tie Garnacho down to an eight-year deal, but the player has reservations about putting pen to paper on a contract so long.
The Argentina youth international is said to be wanted by both Real Madrid and former club Atletico Madrid, and a deal could see a buy-out clause included in his contract, common in several parts of Europe.
It is thought that those close to Garnacho don't want him to sign a contract longer than four-and-a-half years, but United aren't said to be worried about losing the teenager.
He has made 18 appearances for the United first team, and recently set up Marcus Rashford's winner against rivals Manchester City earlier this month.