Maria Sharapova "must accept responsibility" for failing a drugs test and serve her ban, according to Andy Murray.
The five-time Grand Slam winner, 28, revealed on Monday that she tested positive for meldonium in January.
"Clearly if you are taking performance-enhancing drugs and you fail a drugs test, you have to get suspended," said Briton Murray, the world number two.
Russian Sharapova will be provisionally suspended from 12 March.
The former world number one says she has been taking the drug, which was added the World Anti-Doping Agency's banned list on 1 January, for health reasons for the past 10 years.