An inquiry is underway to determine how a 19-year-old Wellington club rugby player has ended up with critical injuries.

He's had brain surgery after Saturday's game, and remains in Wellington Hospital in an induced coma.

Otago University professor of sports medicine David Gerrard told Mike Hosking there's still not enough information to implicate any one event during the match.

"One injury and one event of this magnitude is one too many and of course our thoughts and hearts go out to this young man and [we] wish him a speedy and uncomplicated recovery."

LISTEN ABOVE TO MIKE HOSKING'S TALK WITH PROFESSOR DAVID GERRARD