The World Cup will also be the last time he appears in Irish colours and though he will be lightening his workload from here on in, Corrigan insists that O'Connell has only grown better with age.
"It is quite amazing; three years ago when he was having the difficulties with his back, struggling with injuries and there were concerns over whether he would even make it back you certainly wouldn't have seen this down the line," said Corrigan.
"You'd have thought at that point that getting another couple of years out of him would have been great, and then he could retire to stud and be happy.
"But that just has changed beyond belief in the last couple of seasons, because I can't remember seeing him playing so well.
"I remember watching him in the South Africa game in the November series, and he came out of the lineout, smashed one of the attackers and changed the attacking impetus of the game in the last play, in the 80th minute I think it was.
"And I found myself asking myself, 'where is he getting this energy from? How is this happening?'
"And at that point I was thinking there's plenty left in him yet, so I can fully understand how Toulon might want someone of his experience for a couple of seasons."
Be part of the biggest Tour in the world and register your interest in travelling with the British & Irish Lions to New Zealand in 2017