Johannesburg - Cape Cobras seam bowler Rory Kleinveldt will plead guilty to doping charges, according the SA Cricketers' Association (SACA).
Traces of Cannabis were found in the player's test sample after an anti-doping test conducted in February, Saca said on Friday.
"I need to admit to having acted irresponsibly," Kleinveldt said in a statement.
"I have made a big mistake at a time when I should have known that 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." Tony Irish, the chief executive of SACA, said Kleinveldt was "distraught".
"He knows that he has made a mistake but he is the kind of person who is prepared to front up to it and take responsibility," Irish said.
"Cannabis is a 'specified substance' on the World Anti-Doping Agency's prohibited substances list which means that, although it is banned, it is recognised as being unlikely to have been taken for any performance enhancing reason."
Kleinveldt was handed a provisional suspension, SACA said, pending a formal anti-doping enquiry.
Kleinveldt, who turned 29 on Thursday, has played two Twenty20 International matches for South Africa.
He represented the Proteas at the World T20 tournament in the West Indies in 2010.