Barcelona  midfielder Xavi  has claimed that doping is "very present" in sport and but is certain football doesn not have a problem with drugs cheats.Controversial doctor Eufemiano Fuentes was recently handed a 12-month suspended sentence after blood bags were found in his offices and although he claimed to have clients within football, their names were kept private.And while Xavi has stressed that he is not aware of any doping within the game, he feels that the authorities must be tough on the issue."It's a shame but the issue of doping is very present, not in football, but in sports in general," he is quoted as saying by AS."For me, total prevention or any control is good. People have to be healthy and it's good to have this type of control."In football, I'm sure it doesn't happen. I've never experienced it in 15 years of being a professional and I've never seen it either at Barca or in the Spain national team in any form."We must be very tough on it."Xavi went on to stress that his side would not change in the wake of Jose Mourinho's departure as Real Madrid boss."Mourinho was controversial and very fanatic. I don't know what will happen to him now. What does no change is our values."