The credibility of Alberto Salazar’s defence against doping allegations has been further undermined by an interview he gave about a controversial incident involving Justin Gatlin in 2006.

Switzerland is renowned for being neutral but the country nailed its colours to the mast where drug cheats are concerned by hosting the dirtiest Diamond League race this century.

Usain Bolt blew away any fears about his fitness and fired a major warning to Justin Gatlin as he blasted to his fastest 100 metres of the year on his return to the Olympic Stadium on Friday night.

MATT LAWTON: Seb Coe has said he will feel ‘queasy’ should Justin Gatlin, or any other convicted drugs cheat, win gold at the World Athletics Championships in Beijing.

MARTHA KELNER IN BEIJING: Usain Bolt goes head to head with the two-time drug cheat over 100m and 200m at the World Championships in Beijing this weekend.

Usain Bolt turns 29 on Friday. There might be a modest slice of cake and a rendition of Happy Birthday from his Jamaican team-mates but otherwise the significance of the day will be ignored.

MARTHA KELNER IN BEIJING: The roll call of winners from the first round of the World Championships 100m was almost farcical with four of the seven previously serving drugs bans.

As Usain Bolt fulfilled his final media duties inside the Bird’s Nest stadium after winning 100m gold, with cleaners tidying around him and, a fan draped draped in the Jamaican flag screamed: ‘Yes Usain Bolt!'

American sprinter Justin Gatlin will refuse to speak to British media and the BBC in the future following 'hurtful attacks' and 'biased views' in reports having won silver in the 100m World Championship final.

The parents of controversial US sprinter Justin Gatlin have rushed to his defense as the weight of being public enemy number one in the Olympic arena took its toll on him.

The Jamaican was forced to settle for third in his final solo race at the London Stadium on Saturday after being beaten by the USA's Christian Coleman, who claimed silver, and Justin Gatlin, who won the gold.

Bolt claimed all the headlines as the star of a generation took his final bow in an emotional night in the English capital. And his sporting contemporaries paid homage to his career.

Justin Gatlin was again cast as the pantomime villain by the crowd at the London Stadium on Sunday as he collected his 100m gold medal after beating Usain Bolt to re-gain his world title.

Justin Gatlin is increasingly confident that Usain Bolt will do a U-turn on his retirement and return to the track for Tokyo 2020. Bolt walked away from athletics after the World Championships.

Track and field world champion Justin Gatlin is facing a new doping probe after his trainer and agent allegedly offered to provide performance enhancing drugs to undercover reporters.

American sprinting legend Justin Gatlin fired longtime coach Dennis Mitchell after the reigning 100m world champion was implicated in a doping scandal. Gatlin steadfastly denies doping.

Gatlin has rejected the allegations, for which he is considering suing the newspaper, and has sacked Mitchell, who won 4x100m relay gold for the USA in 1992 before being banned in 1998.

The 22-year-old Brit stormed through on the line to record an impressive season's best of 10.04sec in driving rain, edging out the Chinese pair of Su Bingtian and Xie Zhenye.

Bayern Munich goalkeeper Manuel Neuer has taken to Instagram to show off how he is keeping his reflexes sharp during the football shutdown.  

Bayern Munich have sealed a contract extension for Hansi Flick that will see the head coach remain at the club until 2023.

Chelsea have reportedly made the first move in the race to sign Philippe Coutinho this summer. The attacking midfielder joined Barcelona from Liverpool in a deal worth £145m two years ago.

29-year-old winger Costa featured under Pep Guardiola at Bayern Munich during his spell in Bavaria, but has largely fallen out of favour in Turin this season.

Bayern Munich players will return to training on Monday for the first time since the Bundesliga campaign was suspended. The top flight has been on hold since March 13 due to the coronavirus pandemic.

'Outrageous' transfer fees will become a thing of the past after the coronavirus pandemic, Bayern Munich president Herbert Hainer believes.

First-team stars Robert Lewandowski and Kingsley Coman were seen entering Bayern's training facility on Monday morning as the players returned to action in small groups.

Boateng's relationship with Bayern has soured after he was fined by the club for breaking coronavirus guidelines regarding essential travel, while he is about to enter the last 12 months of his contract.

Muller has been at the Bundesliga giants since 2008 and has put pen to paper on a new deal until June 2023. The 30-year-old crucially kept his social distance for some very unusual photos.

KIT HOLDEN: For days on end, the manicured lawns at Bayern Munich's training ground lay empty. Not a ball in sight, not a Qatar Airways-branded tracksuit to be seen.

The former Liverpool midfielder has failed to make much of an impact at the Nou Camp since his £145m transfer from Liverpool back in 2018. He is currently out on loan at Bayern Munich.

Achraf Hakimi has developed into one of the most coveted full-backs in Europe after spending the last two seasons on loan at Borussia Dortmund from the Santiago Bernabeu side.

Bayern Munich president Herbert Hainer says Thomas Muller is as symbolic to the city as the annual and world-celebrated Oktoberfest.

Bayern Munich and Borussia Dortmund are both said to be interested in Antonio Rudiger. Rudiger has reportedly opened contract talks with Chelsea but has been linked with a move away.

The Frenchman has fallen down the pecking order this season under Hansi Flick, having started just seven games under the new manager at the Allianz Arena.

After failing to break into Zinedine Zidane's starting XI this season, Rodriguez looks set to have two options this summer in the Premier League, with Manchester United and Everton interested.

KIT HOLDEN: The love affair between Bayern Munich and Thomas Muller is one of modern football's immovable certainties. A local boy with a goofy grin, Muller is the apple of Bayern's eye.

The former Chelsea and Bayern Munich star opened up on the couple's health fright, and highlighted that Bernadien had struggled to recover from the virus over a sustained period.

Arsenal were warned against the signings of Shkodran Mustafi and Lucas Perez by their own head of recruitment in 2016, in the same window the club lost Serge Gnaby for just £5million.

Philippe Coutinho's agent has revealed that the midfielder would relish returning to the Premier League at some stage.

Kingsley Coman joined Bayern Munich originally on loan when Pep Guardiola was manager. The French international has praised his former manager as the best 'a winger can have'.

Sagnol, who was working as a scout at Bayern Munich as Varane rose through the ranks at Lens, claimed he got a tip-off about the 18-year-old defender from a friend.

Barcelona are weighing-up a move for Bayern Munich ace Kingsley Coman in the summer, seeing the winger as a backup option for Neymar. The Spanish side will also prioritise a move for Lautaro Martinez.

The Moroccan international has developed into one of the most coveted full-backs in Europe after an impressive two-year loan stint at Borussia Dortmund from Real Madrid.

Phil Thompson believes it is not too late for Philippe Coutinho to reignite his career by rejoining Liverpool in the summer, despite failing to achieve success at Barcelona.

Philippe Coutinho (right) has spent the season at Bayern Munich after being frozen out of the Barca first-team, but the Chelsea target could be handed a surprise return by Quique Setien (left).

Mamadou Sakho has revealed that he turned down Barcelona, Bayern Munich and Arsenal to join Liverpool. The defender joined Liverpool from Paris Saint-Germain in 2013 for £18million.

Everton are reportedlyinterested in signing Torino's Andrea Belotti this summer, with Manchester United and Napoli also pursuing the striker. 

Bayern have a key relationship with Audi, and the German manufacturers have provided every squad member with a new car since 2002, the year they became a shareholder of the club.

The goalkeeper claimed suggestions he wants a five-year contract 'make no sense' given that would take him to the age of 39.

Every now and again - but not often - a player will make the brave decision to move from his current club to their biggest rivals. Here, Sportsmail takes a look at ten transfers between rival clubs.

RB Leipzig striker Timo Werner looks to be edging closer to a move to the Premier League with reports claiming the Chelsea and Liverpool target has started taking English lessons.