Chelsea remain in talks over a deal to sign midfielder Kai Havertz from Bayer Leverkusen.
The Blues' FA Cup final defeat to Arsenal showed the deficiencies that Frank Lampard has to address ahead of next season, and the west London side have already moved to strengthen their squad.
Timo Werner has arrived from RB Leipzig to provide a fresh attacking option up front, whilst negotiations continue for Havertz, with an agreement over the fee the only obstacle standing between a deal being struck.
The midfielder would be Chelsea's third major signing of the summer, with Hakim Ziyech having also arrived at Stamford Bridge, after Chelsea agreed a deal back in February for the playmaker.
And according to previous reports, the Morocco international will attempt to convince Chelsea to sign his former Ajax team-mate Andre Onana this summer.
The goalkeeper is keen to leave Ajax this summer and is thought to be under consideration by Chelsea, with Lampard thought to be keen on signing a replacement for Kepa Arrizabalaga.
Manchester United’s Dean Henderson, Atletico Madrid's Jan Oblak and Burnley’s Nick Pope have also been linked, but according to The Mail, Ziyech wants to try and persuade his new club to sign close friend Onana.
The Cameroon international previously revealed that he is ready to take the next step in his career.
"It was five great years here. But now my time has come to take a step,” he told Fox Sports in April.
“We made that appointment last year.
"I don't know yet what will happen, but my ambitions and agreements are clear."
Along with a new goalkeeper, football.london understands Chelsea want to sign a new left-back, with Leicester City's Ben Chilwell among the chief targets.
There are doubts over Marcos Alonso and Emerson Palmieri's futures in west London, and Blues boss Lampard sees England international Chilwell as a long-term solution for Chelsea in that position.
