Didier Drogba insists Kolo Toure would not deliberate try to cheat and is adamant his Ivory Coast team-mate's failed drugs tests was a 'stupid mistake'.
Manchester City defender Toure is currently suspended after testing positive for a specified substance after last month's derby against United.
Toure's former manager at Arsenal, Arsene Wenger, has claimed the 29-year-old failed the test after taking a diet pill belonging to his wife.
Chelsea striker Drogba has supported Wenger's assertion and has stressed his compatriot would not deliberately try to gain an advantage.
Drogba, in Barcelona to promote his humanitarian foundation at the Global Sports Forum, said: "It would be a difficult situation for us if he is banned because he is one of the most important players, one of the oldest, most experienced players.
"It would be very difficult for us if something like this happens.
"I think we all know how stupid it was, the mistake, and I don't think he did it to improve his performance.
"I think it was just a mistake and we feel sorry for him and he has all our support, and that's the maximum we can do.
"I spoke to him and he was down, but that is normal. He said it was just a mistake.
"There's not a big difference between what is said by Arsene Wenger and what he said (to me)."