Middlesbrough have accepted a bid from Atalanta for midfielder Marten de Roon, Press Association Sport understands.
The 26-year-old Dutchman joined Boro from the Italian side last summer for £12million, but has been linked with a return this summer.
It is understood the Teessiders have now agreed a fee to allow De Roon, who started last Saturday's 1-0 Championship defeat at Wolves, to head back to Italy.
Boro have spent heavily during the summer window with £15m striker Britt Assombalonga heading a list of incomers which also includes Darren Randolph, Ashley Fletcher, Martin Braithwaite, Cyrus Christie and Jonny Howson.