Arsenal and Chelsea fear their Boxing Day Premier League clashes against Wolves and Fulham could be under threat due to a planned tube strike.
Arsenal have sold all 60,000 tickets available for the game at the Emirates Stadium, but access to the ground for both supporters and the club's 1,000 matchday employees could be restricted if the planned strikes go ahead.
Drivers have planned a 24-hour walkout on Boxing Day and on three other days over the next two months.
You have been warned!!