Carlos Soler, a midfielder for Valencia, has been rumoured to have caught the glimmering eye of Mourinho this season as the Spanish side continue to rejuvenate under Marcelino.
At just 20 years of age, he has become one of the success stories at the Mestalla so far this season and netted in an impressive 2-2 away to Real Madrid at the start of the 2017/18 campaign.
What stands out though is his importance to the team and his ability on the ball. A calm player, his crossing and passing accuracy has garnered him 4 assists so far this season, one more than Isco of Real Madrid and Ivan Rakitic.
His long-range ability could be likened to Paul Scholes and David Beckham, but he can also dribble effectively and at a tender age has the years ahead of him to become a better player. A first Spanish cap may be not far round the corner if his performances keep improving.
Both The Sun and Daily Star say Mourinho is willing to splash out over £40 million to get his man, but the midfielder refused to say whether he would be willing to join the Red Devils, speaking last week: "You already know it. I'm focused on Valencia. Regarding those things (the interest from Manchester United) I know nothing.
"It would be foolish to think about those things right now. I have to be focused on Valencia.I have a lot of years left (in my contract) and that's what I have to do".
Of course, with his team doing so well in the league - just 5 points off Barcelona after a 1-1 draw against them last Saturday - staying at a redeveloping club with new ambitions may be the long-term aim for him.
But if Mourinho wants to improve and get the club as far as they can in the Champions League, then a move for Soler may hold the key.
Mkhitaryan has struggled to hold down a starting position at the club, and Paul Pogba, although becoming more influential and scoring goals this season, has yet to lead the midfield by example.
Soler may be the partnership and link-up between Pogba and Lukaku, along with his calm range of passing and shooting, which could ensure they become a force to challenge for the Premier League title in the coming years and the Champions League.
Perhaps though, it would be fair to give Mkhitaryan a chance to find form before splashing out on a player, and if Soler does come in, he is not guaranteed instant success, despite being a highly-promising player.
It took a while for both Spanish duo Herrera and De Gea to settle into the English game. If Mourinho is keen to sign the Valencia however man, then he will do so in the aim to develop long-term future of Manchester United, and indeed himself at Old Trafford.