Marcos Alonso will ask to leave Chelsea, according to Spanish publication Sport.
It comes amid reports that Barcelona, who have agreed the signing of Andreas Christensen, are also looking to bring in Alonso and captain Cesar Azpilicueta from the Blues.
Alonso has been tipped to leave Stamford Bridge during successive transfer windows but has ended up staying.
However, it appears he is keen to join Barca and will tell Chelsea he wants to move on.
The return of Ben Chilwell from a long-term knee injury leaves Alonso facing the prospect of very limited game time should he stay.
And the potential departure of Azpilicueta along with Christensen and the Real Madrid-bound Antonio Rudiger means Chelsea will certainly need to sign defenders this summer.
Head coach Thomas Tuchel said at his press conference after Sunday’s 2-1 win over Watford that he hoped to have new players on board for the start of pre-season.
“This is the plan,” he said. “Hopefully we can do this and have everybody ready for the pre-season.
“It’s a pre-season where you have three or four weeks together and we need to be quick and fast to adapt to the qualities and personalities of these new guys.
“But first of all we need to be able to sign, be smart (about) who we sign and be on-point.”