Anti-doping officers tested Riyad Mahrez after Pep Guardiola revealed Manchester City’s fears the winger had taken a banned substance.
The Algeria international was left out of last weekend’s Community Shield because club doctors couldn’t verify the sinus medication he’d taken.
UK Anti-Doping then turned up at the Premier League champions’ academy this week to test Mahrez, who has now been cleared to face West Ham in City’s opening game on Saturday.
Guardiola confirmed: “He had a little surgery after the African Cup on his nose so he could breathe better. It’s a normal situation, the doctor, who was not from the national team, didn’t send the necessary (information). That was the only reason why (he didn’t play).
“Our doctors came to me and said they did not know exactly. Every time you take something you have to inform the club and make the lists. Everyone knows it.
“We pass one or two controls every month here. We didn’t have it in that moment. He did it in Algeria. So it was a precaution, we had to be careful. It was better not to use him, that was the reason why.
“But after the last week, anti-doping have made the test. Everything is clear and fine. He can play.”
Mahrez is likely to be given more opportunities to establish himself at City this season, following confirmation Leroy Sane will be out for around seven months with anterior cruciate ligament damage.
The Germany winger will undergo surgery at knee specialist Dr Ramon Cugat’s clinic in Barcelona next week.
The injury has wrecked his chance of a move to Bayern Munich this summer.
Guardiola said: “Normally this kind of injury in the ACL is six or seven months. Hopefully in February or March he can be back with us.
“It’s bad news as in three seasons we’ve had three ACLs. He’s young and he will recover well hopefully in terms of the surgery next week.
“All the people will help him, he will feel alone and we help him to feel as comfortable as possible.”
He added: “The quality from Leroy we don’t have it. A little bit (Raheem) Sterling has it, but you can’t find it around the world, that attacking the space, that speed. Riyad doesn’t have it - he’s not a substitute for Leroy.
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“But my option during the first few games during the summer, I was quite impressed.
“He didn’t play too much (last season) because of Bernardo (Sliva) and Sterling - but with Leroy absent we have more space, a lot of games, one less forward player, so he is going to play.”
