First-choice fly-half Cooper tore his ACL in Australia's Bronze Medal Match with Wales at the 2011 World Cup and is expected to remain out of action until April at the earliest.
But a last-minute rush to catch a plane means the 23-year-old has been given a timely boost as his team-mates step up their preparations for the new Super Rugby season.
"They said the plane was going to leave without us so we had to run for the gate," said Cooper, who raced 500 metres from one side of the airport to the other.
"I started running and I thought 'I'm not supposed to run', so then I started walking. But we kept getting calls over the speaker saying 'This is the last call' and we were right down the other end of the airport.
"I jumped on the plane and I told the physio 'I've had my first run, and my knee feels good'!"
And while the unexpected jog doesn't mean Cooper will be back in action any time soon, it has heightened his confidence as he enters an important phase of his recovery.
His Queensland Reds side face the Brumbies in their first pre-season fixture this weekend but Cooper will hit a landmark of his own when he goes for his first official solo run with physios in Cairns.
"I'm really looking forward to it," added Cooper.
"I do I know that little jog through the airport would have helped.
"It's a big tick on the comeback trail for me. It's the end of basically all the hard little work you need to do to get the knee into a position to run."