Man Utd lining up David de Gea's replacement?

Manchester United are reportedly keeping tabs on Porto goalkeeper Diogo Costa ahead of the summer transfer window.

De Gea has been in fine form for the Red Devils this campaign but he has made several world-class saves for the club.

However, the Spaniard has been average with his overall distribution and has not looked confident with the ball at his feet.

Hence, the Red Devils are pondering a potential successor and A Bola cite that United scouts were once again watching Costa.

Costa has been monitored by the club on numerous occasions this term and he was watched closely once more on Saturday.

The Portuguese signed a new long-term deal with Porto earlier this season which has increased his release clause to £60m.

Despite this, he continues to be tracked by clubs including Chelsea, who are also eyeing a new shot-stopper this summer.

United are bound to face competition in the pursuit of Costa this summer. Tottenham Hotspur have also been linked with him.