N’Golo Kante has left Chelsea’s pre-season training base in Japan and returned to England for treatment on a knee injury.
Kante picked up the injury at the tail end of last season and will continue his recovery away from the rest of the squad as they gear up for the new campaign.
A statement on the club's official website said: "N’Golo Kante has travelled back to the UK to continue his rehabilitation for an injury connected to the knee problem he sustained at the end of last season."
The news of the midfielder's withdrawal from the camp comes less than two days after the Blues' 1-0 friendly defeat to Kawasaki Frontale.
Speaking before the trip to Japan, Chelsea head coach Frank Lampard said of Kante: "[He's] still feeling the effects of his injury from the end of last season, which we know with the Europa League final.
"It's not a problem, we know he's a fit boy, we know he's got a great attitude."
The France international is expected to miss the Blues' upcoming friendly match against Barcelona on Tuesday as a result of the treatment, which, it is hoped, will help him get ready in time for the season kick-off.
Lampard has deployed a number of different midfielders during pre-season thus far, with the likes of Ross Barkley, Kenedy, Mateo Kovacic, Jorginho and Mason Mount all featuring.
And Kante's fight to regain fitness before Chelsea's Premier League opener against Manchester United on August 11 may provide an opportunity for one of those players to stake a claim for a place in the team.
More positively for the Blues, however, goalkeeper Kepa Arrizabalaga and striker Tammy Abraham returned to training with the group after recovering from illness, with both in contention for the Barca clash.
The game against the Spanish champions is set to take place in Saitama Stadium in Japan and it will be followed by a meeting with Reading at the Madejski Stadium five days later.
The Blues then travel to Austria to face RB Salzburg and Bundesliga side Borussia Monchengladbach provide their final warm-up opposition ahead of the new season.