But a sports medicine professor says a professional athlete cannot afford to binge and top sides have moved against heavy drinking.
All Black Cowan kept his playing contract on Tuesday but was fined $3000 and told if he consumed alcohol between now and December his New Zealand Rugby Union contract would be terminated.
Cowan (26) is on the bench for the All Blacks in the first Tri-Nations test against the Springboks in Wellington on Saturday night.
He is also expected to appear in Wellington District Court today on a charge of disorderly behaviour following an incident in Dunedin on April 5.
This is his third charge of disorderly behaviour in recent months.
Former All Black flanker and fellow Southland player Paul Henderson said he had no doubt Cowan would handle the alcohol ban.
"The boundaries have been set and he knows exactly what is expected of him now," Henderson said yesterday.
"As long as he has support around him, which the All Blacks will give him, then he should be fine."
It would not be hard for him to stop drinking in the team environment.
Henderson said Cowan was probably a bit lippy at crucial times, which had led to the arrests, as he was a "cheeky" halfback, but he still had everyone's respect in the Southland community, and not just for his on-field talents.
Former All Black prop Richard Loe said the publicity over Cowan and his drinking was "over the top" and he did not consider Cowan's behaviour a big issue.
He said it would not be hard for Cowan to stay alcohol-free, as he had support from the NZRU, and Cowan knew he simply could not drink.
Loe said there was a motto when he was in the All Blacks that you could "go to the edge but never fall off".
"And if you did fall off, then your team-mates would be there to yank you straight back up," Loe said.
"But it is all about not putting yourself in the situation when something like this [arrest] happens."
He said non-drinkers were treated no differently to any other team member when he played.
There was no booze culture in the All Blacks and calls for Cowan to be banned were wide of the mark, Loe said.
"People have been talking about a booze culture for 100 years. My grandfather and father talked about that."
Coaches had slapped alcohol bans on players with no publicity when he played, Loe said.
University of Otago associate professor of sports medicine David Gerrard said it would be inconsistent of an Olympic athlete to consider having a long night on the town leading up to an important event.
"A professional athlete in full training does himself no good if he goes out drinking large amounts of alcohol," Prof Gerrard said.
Prof Gerrard, who is a life member of Sports Medicine New Zealand, said it would take hours if not days to recover after a large intake of alcohol.
Most top sport sides were now frowning upon heavy drinking, and the All Blacks were no different.
