Barcelona midfielder Lionel Messi missed yesterday's open training session.
Barca claimed Messi was suffering from a stomach upset, just hours after defeat at Real Sociedad.
Messi apologised to fans on Facebook:
"I would have liked to have been at the traditional Christmas training session. I have never missed it before but I have no control over setbacks such as this. My wish is that everyone's dreams will become a reality in 2015. Hugs."