Former South Africa Twenty20 seamer Rory Kleinveldt admitted on Friday that he took the banned drug cannabis last month.
The Western Cape Cobras star has been provisionally suspended and will plead guilty to doping charges, the South African Cricketers' Association said.
"I admit to having acted irresponsibly," Kleinveldt said in a statement. "I have made a big mistake and should have known what I was doing was wrong.
"As a person and a professional cricketer, I need to take responsibility for this and deal with the consequences of my actions."
Cannabis is a 'specified substance' on the World Anti-Doping Agency prohibited substances list.
This means that although a banned substance, it is widely accepted that cannabis is not usually taken for performance-enhancing reasons.
Kleinveldt, who turned 29 this week, represented South Africa at the World Twenty20 in the West Indies two years ago.