Chelsea have agreed a £12million deal with Basel for Portugal U20 international defender Renato Veiga.
The 20-year old left-sided centre back is leaving Basel's training camp in Seefeld, Austria to undergo a medical.
Veiga can also play at left-back and midfield. He was signed by Basel last summer as a replacement for Riccardo Calafiori, the Italy international, who they sold to Bologna.
Veiga made 26 appearances for Basel last season, scoring two goals - including a free-kick against FC Zurich.
Chelsea have already had a busy summer, with the signings of Kiernan Dewsbury-Hall, Omari Kellyman, Marc Guiu and Tosin Adarabioyo.
Calafiori became an option for Chelsea this summer but is currently talking to Arsenal over a move there.
Mail Sport reported that Gunners boss Mikel Arteta is keen to bring in defensive reinforcements after finishing runners-up behind Manchester City for the second consecutive Premier League season.
The Italy centre-back impressed during their tepid Euro 2024 campaign - playing the entirety of every group game - after a breakthrough season with Bologna that saw the club qualify for the Champions League.
Liverpool have also been linked with a move for the 22-year-old but have no interest in challenging Arsenal or other clubs for the rising star's signature.