Chelsea striker Diego Costa appeared to suffer an injury while in training ahead of Saturday's end-of-season friendly against Thailand All-Stars.
The Spain international impressed during his debut season with the Blues as he helped guide them to Premier League glory, but his campaign fizzled out at the end due to injuries.
The 26-year-old, who returned to fitness two weeks ago, winced in pain after being tackled by John Obi Mikel during a training session at Rajamangala Stadium on Friday, and limped off the field without his boot, according to the Daily Mail.
Despite the potential injury, Costa was on hand to sign autographs for fans with his teammates once the session came to an end.