Manchester United face a major problem over the future of young star Kobbie Mainoo . With just two years left on his contract, the 19-year-old midfielder is rumoured to be considering an exit from Old Trafford this summer. Talks are reportedly ongoing between Mainoo's agents and United chiefs about a contract extension, but it's been claimed that he might reject a new deal in favour of a move abroad. There are also suggestions that United could be tempted to cash in on the homegrown prospect if they are offered at least £70million, with Chelsea previously showing interest. Ex-United goalkeeper Ben Foster has now sounded a cautionary note, suggesting that Mainoo, who's currently earning a modest £20,000 a week, might start feeling disgruntled. The fact underperforming teammates such as Casemiro and Mason Mount are earning considerably more could add to the youngster's frustration over his pay packet Despite a season of ups and downs, Foster has touted Mainoo as a " world beater" in the making. "It must really annoy Kobbie Mainoo, because he must be looking around at some of the players that are on crazy wages that are nowhere near as good as him," said the former Wrexham goalkeeper on his Fozcast podcast. "They don't put in any of the performances that he puts in, and they're earning three, four, five or even six times the amount he is. I thought that after the Euros, he was going to go on to be a world beater this season." He added: "I still think there's a world beater there as well and it's probably mental fatigue or a bit of burnout. I think we will see an absolute player." Despite Mainoo's representatives reportedly pushing for a hefty £150,000-a-week wage from United, doubts linger over the feasibility of such a deal, especially with Sir Jim Ratcliffe's intention of slashing player salaries. Foster voiced his opinions while also questioning Mainoo's leverage, with United having an option for an additional year on his contract. Foster said: "He's not in any position right now because of circumstances to go making demands. He's still got three years left on his contract with an option. "If he was at Chelsea, he'd be on £150,000 per week so that's his argument. But then the club come at it from their perspective and go, 'Well, you've still got three years left on your contract.'". While no direct contact has been made with other clubs, the uncertainty surrounding Mainoo's contract situation is likely to attract attention from teams across Europe. Spanish outlet Don Diario reported last year that La Liga giants Real Madrid had taken notice of Mainoo. Before his standout season last year, the midfielder had a spell on the sidelines due to injury. During this period, Mainoo decided to learn Spanish to keep himself busy. In a conversation with The Telegraph last summer, Mainoo revealed that he began taking Spanish lessons via Zoom while recovering from an injury during pre-season. He admitted that it was tough to maintain once he returned to the pitch, but it's a pursuit he enjoyed and hopes to return to. Join our new MAN UTD WhatsApp community and receive your daily dose of Manchester United content from Mirror Football. We also treat our community members to special offers, promotions, and adverts from us and our partners. If you don't like our community, you can check out any time you like. If you're curious, you can read our Privacy Notice.