MELBOURNE: Canada's Milos Raonic has found a novel way to help alleviate the tension that inevitability surrounds a grand slam tennis tournament, he has taken to wearing a mouth guard.

Reporters spotted the mouthguard the tall 25-year-old, whose languid movement around court obviously belies the nervous tension he is fighting, during his 6-1 6-4 6-4 Australian Open victory over Lucas Pouille on Tuesday.

"Just to not grind my teeth while I play," Raonic said when asked why he was wearing a protective device in a sport not known for its contact between players.

"It just causes stress and headaches sometimes," he added. "I guess maybe its just a way to calm down."

Raonic said he had been advised to wear the guard to alleviate the effects of teeth grinding, not by a dentist, but by a chiropractor.

"Maybe it's helping my back," he added.

While the mouthguard may help him calm down in the heat of a tournament, Raonic said he was now using it virtually all day.

"I wear it all the time other than when I'm eating, so I got used to it pretty quickly," he said.

"Maybe I fiddle it with it too much while I play, but other than that it's pretty much there all the time."

Raonic, who beat Roger Federer to claim the Brisbane International title before the season opening grand slam, will play either Tunisia's Malek Jaziri or Spain's Tommy Robredo in the second round.