Jane lime in Cock's celery juice? Might need to be careful it doesn't upset his acidity levels 
I was thinking about that watching the programme. On court, all you had was Robinsons barley water or Coca-Cola. Off court, you went for a few beers (and perhaps some dope, if you were so inclined!).
Can you imagine what that would do to Cock's equilibrium? He'd have a breakdown 