Chelsea are back on the trail of Brazilian centre-back Doria after dispatching a scout to watch him in Marseille's draw with Angers.
The Blues have been tracking the 21-year-old defender for three years, with Doria, who used to captain Brazil’s Under-20 side, having previously been compared to PSG star Thiago Silva.
He was sent out on loan to Granada last season but has established himself in the Marseille side this term, starting in seven of their eight Ligue 1 matches.
Chelsea's top French scout Guy Hillion was at the Stade Jean Bouin in Angers to assess his performance in the 1-1 draw last weekend.
The ex-Botafogo star was reportedly on the radar of Barcelona, Juventus and AC Milan before his £4million move to France in 2014.