The forward shone last season, helping the Pensioners win the title in his first campaign in English football.
However, he has endured a mixed campaign this time around, wholly failing to make an impact under Jose Mourinho during the first half of the season, before gradually rediscovering his form under interim boss Guus Hiddink.
While Costa may have returned to the scoresheet, he still carries a lot of baggage, as he demonstrated against Everton in the FA Cup last weekend when footage appeared to show him biting Gareth Barry.
Fichajes report that United are considering a move for the forward, and are willing to offer over €45 million to bring the Spain international to Old Trafford.
However, the Spanish source state that they face considerable competition from Costa’s former club Atletico, with Diego Simeone keen on bringing the tenacious forward back to La Liga.
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