Andy Murray says Viktor Troicki and Marin Cilic were ''unprofessional'' and have no excuses for the doping offenses which led to their suspensions.
Troicki had an 18-month ban reduced to 12 months this week for skipping a blood test in April, though he provided a urine sample which proved negative. Cilic served a four-month ban after testing positive for a banned stimulant in May, but claimed he had not intended to ingest it in a glucose tablet bought at a pharmacy.
Speaking to the BBC, Murray said there ''almost has to be zero tolerance'' for tennis to stay credible in the public opinion.
The Wimbledon champion added: ''Whether either player was intentionally cheating or not - we don't know that, and I don't think either of them are like that -but both of them were unprofessional.''
