Eden Hazard and N'Golo Kante returned to Chelsea training on Monday but there was no sign of wantaway goalkeeper Thibaut Courtois.
Reports suggest Real Madrid target Courtois did not report to the team's Cobham base and he was conspicuously absent from an image gallery posted to the club website.
Maurizio Sarri had hoped to hold face-to-face talks with the Belgium star in an attempt to gauge his level of commitment.
Instead, the apparent no-show only serves to cast further doubt over the 26-year-old's future at Stamford Bridge just five days out from a season-opening trip to Huddersfield Town.
Chelsea will, however, be encouraged by the timely return of Hazard and Kante, the pair having been linked with Madrid and Paris Saint-Germain respectively.
They were joined by fellow World Cup participants Olivier Giroud, Gary Cahill and Michy Batshuayi ahead of Tuesday's International Champions Cup clash with Lyon.
Meanwhile, the Blues have confirmed defender Fikayo Tomori has signed a contract extension through to the end of the 2020-21 season.
The England youth international will spend the current campaign at Derby County after Frank Lampard added a second Chelsea loanee, Mason Mount having arrived in July.
