Luke Adams leaves court yesterday and (right) the once promising ruckman in his days playing for Swan Districts.

Luke Adams leaves court yesterday and (right) the once promising ruckman in his days playing for Swan Districts.

Former promising Perth footballer Luke Adams remembers buying a 700 millilitre bottle of vodka after a big game in late April 2011.

But after that he recalls nothing - a court has heard.

The ex-WAFL ruckman's next memory was waking up in Royal Perth Hospital with mitts on his hands, he told the District Court of WA on Monday.

He didn't know how long he'd been unconscious, and would later find out it was weeks, not hours.

He couldn't even "clearly" remember playing his last game of football on April 30, 2011, he said.

Mr Adams suffered extensive injuries after, Dylan Winter, 20, the man facing trial charged with inflicting grievous bodily harm, threw a single punch knocking the 198-centimetre athlete to the pavement, the court heard.

While Mr Adams, 21, was recovering at RPH and then a rehabilitation centre in Shenton Park, a foundation was established in his name to tackle antisocial behaviour on Perth's streets.

But Mr Winter's lawyer Craig Eberhardt claims it was Mr Adams who threatened to "smash" his client in the early hours of May 1, 2011, prompting the punch in self defence.

Although he has no memory of going out that night, Mr Adams could identify himself on CCTV footage taken outside The Deen nightclub that showed him with a group of friends leaving about 2am on May 1.

Footage from another CCTV camera played in court showed two man resembling Mr Adams and his teammate Travis Gray dancing past the Hog's Breath Cafe at 2.32am.

Mr Adams said he could not remember whether or not he was drunk.

But his blood alcohol reading after he was taken to hospital with bleeding from the head and nose from the punch was 0.22 per cent, the court heard.

The two football players had encountered Mr Winter with a group of his friends on Lake Street shortly before 3am.

The defence case argues Mr Adams provoked the punch by saying "I'm going to smash you," to Mr Winter, who had made a spur of the moment decision - faced with a larger opponent - to strike first and run.

Under cross examination Mr Adams said he could not say whether he had played a role in provoking the attack, because he had no memory of it.

The court also heard evidence of a violent brawl between Mr Winter's group of friends and bouncers at The Library nightclub shortly before the encounter with Mr Adams, which prosecutor Amanda Forrester argued spoke to Mr Winter's state of mind before the punch.

Ms Forrester argues there was no lawful reason for the punch, which she claims was in retaliation to Mr Adams "mouthing off", rather than an action of self defence.

Mr Winter sent a friend a text message after the altercation saying "the guy was mouthing off, he got what he deserved," Ms Forrester told the court.

The trial has been set down for three weeks.