'It's devastating for him' - Awful tackle sees Tahs recruit Perese sent off under new red card law variation

NSW Waratahs coach Rob Penney says he's heartbroken for Izaia Perese after his comeback was derailed by a red card for a dangerous tackle that could see him out for half of the Super Rugby AU season.

The former Queensland Reds back was sent off after 36 minutes of the opener against his old team when he flipped Hunter Paisami in an unnecessary follow-up to a tackle that had already forced the ball loose.

It left the Waratahs a man down for 20 minutes until Perese was able to be replaced under the new rules.

However, the Reds scored all their points either side of that in a 41-7 rout at Suncorp Stadium.

After leaving the Reds, Perese's short stint at the NRL's Brisbane Broncos ended after he was charged with drug offences.

He had found a new home at the Waratahs, via a French rugby cameo, on a one-year deal.

But the code's harsh treatment of dangerous tackles and Super Rugby AU's eight-game regular season before a two-week finals system means he could watch most of that from the sidelines.

"It was a fair call no doubt, but I just feel so heartbroken for Izzy," Penney said.

"He's a talented young kid who's come back to re-establish his reputation and that's a tough start for him.

"He'll get a lot of support from us because we love him but it's devastating for him, no doubt.

"He's playing his old club, probably a bit of over-arousal, and we tried to keep the heat off him this week for that very reason - but he's a competitive man and he overplayed his card."

Suspected ankle injuries to new captain Jake Gordon, who was among the best on ground before being caught awkwardly in a tackle, and Joey Walton, compounded the misery for Penney in what was a Super Rugby record loss to the Reds.

"It's hard to tell at the moment ... (Gordon's) on crutches but we'll see," Penney said of his captain.

"It'd be a big loss, he's just been made captain so there'd be implications but we have a great young leadership group doing a great job.

"The Reds opened us up and at 21-7 the red card occurred, not to concede another point for that 20-minute block was courageous ... but we certainly weren't good enough."