There are strict rules in football which regulate what substances a player can take, ensuring no one can get a competitive advantage that isn't earned by hard work.
Throughout history, athletes across the sporting world have looked for those marginal gains to help them achieve their goals. Unfortunately, those gains are sometimes found in an illegal manner.
Greats like Rio Ferdinand, Pep Guardiola and Diego Maradona have been in trouble with authorities during their playing careers. Sometimes it is an honest mistake, while other cases are less clear.
Here are some of the highest-profile doping cases football has seen over the years.
1. Paul Pogba
World Cup winner Paul Pogba returned to Juventus from Manchester United in the summer of 2022 with the hopes of revitalising his career. His 2022/23 campaign was blighted by injuries, being limited to ten appearances in all competitions.
His return in 2023/24 was hotly anticipated in Italy but after facing Udinese in August 2023, he tested positive for testosterone. The Frenchman played against Bologna and Empoli before news broke of his positive test and he was suspended in September 2023, pending an investigation.
Pogba argued the substance was ingested accidentally but was still handed a four-year ban, which he is expected to appeal at the Court of Arbitration for Sport (CAS).
After the ruling Pogba released a statement saying he was 'sad, shocked and heartbroken that everything I have built in my professional playing career has been taken away from me.' He continues to deny the charges.
Turning 31 years old in March 2024, Pogba could be 35 by the time he plays pro football again if his appeal is unsuccessful.
2. Andre Onana
Man Utd goalkeeper Andre Onana spent time away from the game after he tested positive for a substance called furosemide in February 2021. He was an Ajax player at the time and fell foul of an out-of-competition check by UEFA.
The UEFA Appeals Body reduced the shot-stopper's ban from 12 months to nine in June 2021 after they accepted his story of having accidentally taken his wife's prescription medicine while searching for an aspirin.
Onana stayed at Ajax during his ban before joining Inter where he rebuilt his career, eventually earning a move to Man Utd.
3. Rio Ferdinand
There are two examples of Rio Ferdinand being looked at closely by authorities.
In 2003 while at Man Utd, Ferdinand failed to show up for a routine drug test. He was subsequently handed an eight-month ban for not providing a sample.
Ten years later, Ferdinand found himself in trouble again, this time at Queens Park Rangers. The former England centre-back accidentally missed another drug test and was handed a one-game suspension and a £25,000 fine.
4. Pep Guardiola
He may be one of the greatest managers the game has ever seen, but Pep Guardiola was in trouble during his playing career. In 2001, the Spaniard was playing for Brescia in Italy.
The Spaniard tested positive for the banned substance nandrolone, denying it every step of the way but still being handed a four-month ban. His denial went on for a long time and he was eventually cleared of all charges by the Italian federation in 2009.
As part of the ban, Guardiola had been found guilty by a court in Brescia and given a seven-month suspended prison sentence. That verdict was also overturned in 2009.
5. Diego Maradona
Where to start?
Diego Maradona's name is synonymous with football for many reasons, most of them positive, but he is also the first name that many think of when you say 'doping in football'.
He first tested positive for cocaine in 1991 whilst playing for Napoli and he was banned for 15 months. He was then sent home from the 1994 World Cup in the USA after the banned substance ephedrine was found in his system.
Finally, he tested positive for ephedrine again in 1997, this time whilst playing for Boca Juniors. That led to a three-month suspension. Whether this tarnishes his career, or was all part of the charm, is for you to decide.
6. Edgar Davids
Edgar Davids was a fantastic player in his day who became something of a cult hero thanks to his eyewear. That doesn't mean the rules don't apply to him, though, and his time at Juventus was tarnished with a ban.
He was given a five-month ban in 2001 by the Italian authorities after testing positive for the banned substance nandrolone. He was 28 years old at the time of the ban.
7. Adrian Mutu
Another player who has had more than one problem with doping in the past, Adrian Mutu saw his Chelsea career come to an end in 2004 when he was caught using cocaine. He was sacked by the club and banned for seven months.
In 2010, he was in trouble again. Playing for Fiorentina, Mutu was handed a nine-month ban. He had told prosecutors that the traces of sibutramine found in his tests were the result of slimming tablets given to him for his mother.
In 2018, his latest attempt to avoid paying Chelsea £15.3m in compensation failed, having been through multiple courts and appeals processes.
8. Samir Nasri
Samir Nasri fell foul of the rules in 2017 as he was handed a six-month ban for the use of illegal substances, which was then extended to a massive 18 months thanks to a UEFA ruling.
UEFA stated that the ex-France international was found guilty of using a "prohibited method" in violation of the World Anti-Doping Code and UEFA's own anti-doping rules.
He had visited Drip Doctors, a clinic in Los Angeles that posted a picture of him on social media stating that they had provided him with a drip "to help him keep hydrated and in top health during his busy soccer season."
UEFA opened disciplinary proceedings against Nasri and it was revealed that the Frenchman had received 500 millilitres of hydration from Drip Doctors in the form of sterile water. This is 10 times more than what the World Anti-Doping Code and UEFA’s anti-doping regulations allow.
He went to the clinic because he felt ill and was vomiting, so he received treatment in his hotel room and posed for a photo with the organisation's co-founder Jamila Sozahdah, an image that became very popular on social media.
To make the whole episode even weirder, tweets started coming from his account saying he had also been provided with a “full sexual service” by the clinic. He later claimed to have been hacked, but it led to the end of his relationship with his girlfriend. By the age of 34, Nasri had retired, citing this episode as one of the main reasons why.
