The International Tennis Federation has revealed that tennis players would not be able to plead ignorance if they test positive for banned substances.
This was made known after former world number one Maria Sharapova, 29, had a two-year ban reduced to 15 months.
The Court of Arbitration for Sport (Cas) had ruled she was not told about a change in the drug’s status.
She tested positive for meldonium less than a month after it was banned.
The ITF said “appropriate steps were taken to publicise any changes”.
But, in a statement, it added: “Nonetheless, we have reviewed, and will continue to review, our processes for communicating changes to the prohibited list to players with the aim of ensuring that no player can claim that they had not been fully informed.”
Sharapova is a five-time Grand Slam winner and was Forbes’ highest-paid female athlete for 11 consecutive years, until American Serena Williams moved above her this year.
The Russian, whose suspension is backdated to the date of her first positive test on 26 January 2016, can return to action on 26 April 2017.