Manchester United have already conceded 14 goals in seven Premier League games this season.
United boss Erik ten Hag is weighing up his goalkeeping options, having stuck with long-term number one David de Gea since taking over.
Reports have emerged that United and De Gea are set for talks on his future, with the 31-year-old's deal to expire in 2023.
TOP STORY – MAN UTD EYE COSTA AS DE GEA REPLACEMENT
Manchester United's goalkeeper situation is in flux, with the club interested in Porto custodian Diogo Costa, according to Metro.
United have sent scouts to watch the 23-year-old goalkeeper, who has seven caps for Portugal.
The Red Devils are looking for De Gea's successor, with the Spaniard seemingly not suiting Ten Hag's possession-based style.
United also have 25-year-old England international Dean Henderson out on loan at Nottingham Forest.
ROUND-UP
– O Jogo claims former Olympiacos manager Pedro Martins could be the latest Portuguese coach to take over at Wolves, following Bruno Lage's dismissal on Sunday. The Telegraph reports that under-fire Sevilla boss Julen Lopetegui may be considered and Celtic manager Ange Postecoglou has also been discussed.
– Juventus and Real Madrid will rival Liverpool in the race to sign Belgian midfielder Youri Tielemans from Leicester City, claims Calciomercato.
– LaLiga pair Sevilla and Valencia are both interested in Manchester United forward Anthony Martial, reports Todofichajes.
– Tottenham and Juventus target Nicolo Zaniolo is set to pen a new deal with Roma, re-committing on a €4million per-year deal until 2027, according to Calciomercato.
– Everton's Venezuela international striker Salomon Rondon has interest from UAE club Sharjah FC but is likely to stay with the Toffees, reports Liverpool Echo.