Damning rumours have emerged over alleged widespread of use of adderall among top tennis players following a Davis Cup champion’s shock doping ban.

Fernando Verdasco has received a two-month ban following a positive test for the ADHD medication methylphenidate at a second-tier ATP Challenger event in February.

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Verdasco, 39, had not renewed a Therapeutic Use Exemption (TUE) and the International Tennis Integrity Agency said the Spaniard “did not intend to cheat” and the violation was “inadvertent and unintentional”.

But he has nonetheless been issued with the ban under the game’s rules.

The former top-10 player accepted a voluntary suspension that runs until January 8, 2023 – eight days before the Australian Open is due to begin.

Following the news, speculation began within the tennis community that ADHD medication – specifically adderall – is being used for reasons other than intended.

Fernando Verdasco (centre) celebrates winning the 2009 Davis Cup with Spain. Credit: Getty Images

Tennis great turned pundit Pam Shriver poured fuel on the fire when she shared a rumour heard ‘through the grape vines’.

“Through grape vines of pro tennis, I hear that many players are on ADHD meds to help sharpen focus and concentration in a manner that brings up integrity questions,” Shriver said.

“Are ADHD meds the meldonium for the brain? Wonder how many current players have asked for a TUE for ADHD recently?”

7NEWS.com.au is not suggesting Verdasco, who has been granted a new TUE, or any particular players are engaging in misconduct surrounding ADHD medication.

Meldonium was the heart medication former world No.1 Maria Sharapova took for several years before it was added to the banned substance list.

Ben Rothenberg, leading tennis journalist at The New York Times, added to the adderall storm when he shared input from an anonymous male tennis player.

“One ATP player told me today he estimates ‘half of top 100 is on it…maybe more’,” Rothenberg wrote.

“And not because they have trouble focusing while doing their homework.”

He suggested adderall use has sparked several conversations among players.

“Lots of cynicism about the TUE system within the locker room,” Rothenberg added.

Meanwhile, Australian tennis star Nick Kyrgios said he was not suprised by the news of the Spaniard’s drug ban.

Kyrgios and Verdasco have a long-running feud dating back to 2018.

“Can’t say I’m suprised with this one,” Kyrgios tweeted on Thursday.

Verdasco was ranked as high as seventh in the world in 2009 but has slid down the rankings to now sit at 125.

He won the Davis Cup three times with Spain and achieved a best grand slam result of semi-finalist at the 2009 Australian Open.

Lleyton Hewitt and the Aussies celebrate after historic Davis Cup win

Lleyton Hewitt and the Aussies celebrate after historic Davis Cup win