Knowing size matters, NSW Waratahs coach Michael Cheika will unleash giant Fijian Taqele Naiyaravoro on the Lions in Sunday’s Super Rugby match at Allianz Stadium.

He’s just not sure when or for how long.

Cheika recruited the 190cm tall, 120kg wrecking ball last month from Wests Tigers in the NRL and has named the winger on the bench for his Waratahs debut after he bagged two tries for Parramatta in Sydney club rugby last weekend.

Cheika has high hopes for Naiyaravoro, but doesn’t want to rush his progress following his code switch.

“He’s got rugby knowledge so it makes it a bit easier,” he said.

“He’s grown up playing the game, so it wasn’t that far a stretch to return back into the game; he knew his work around rucks etc.

“Obviously he’s got some good parts of his game that have come from league, like his ball carrying.

“But it’s still going to be a measured entree into Super Rugby for him, if he gets any time at all.”

The Waratahs are adamant they’re not underestimating the Lions, but Cheika admits giving their rookie recruit a taste in a home game against the competition’s 11th-placed outfit is the best way to blood Naiyaravoro.

“It’s probably just about getting in there, getting a look at the atmosphere, getting pitchside seeing how fast the game’s going and, if he gets a chance to have a run, we’ll throw him out there,” Cheika said.

“I wouldn’t dare risk anyone in that situation who wouldn’t equip himself.

“If we don’t have a go and have a look at him now, we may not get a look at him at all this season because it’s getting shorter and shorter as the year goes on.

“No risk, no reward I say.”

In the only change to his starting team that beat the Hurricanes last outing, Cheika has promoted 140kg lock Will Skelton to the second row in place of Jacques Potgieter.

Potgieter suffered a leg injury against the Hurricanes and only trained for the first time since on Thursday.

Cheika also believes the Waratahs will need Skelton’s size and power against the Lions.

“They’re certainly a physical outfit from what I’ve seen of the Lions this season,” he said.

“They’ve taken it to the opposition, in particular in the scrum.

“They’ve been excellent in the scrum. They’ve pretty much dominated nearly every opposition that they’ve come up against, or they’ve had a really good contest with them, and it’s going to be a big battle for our forwards out there.”