Manchester United are reportedly keen on signing Borussia Dortmund defender Marc Bartra.
Manager Jose Mourinho is believed to be keen to bring in a defensive partner for new signing Victor Lindelof.
The club were interested in re-signing Michael Keane from Burnley, but the 24-year-old opted to join Everton on a five-year deal on Monday.
According to AS, Mourinho has turned his attention to Bartra, but Dortmund are unlikely to entertain an offer as they only signed the Spaniard from Barcelona last year.
Meanwhile, reports have claimed that Mourinho is frustrated with the club for the lack of transfer activity this summer.
Lindelof is the only player to arrive at the club this summer so far.