But Italian playmaker Terry Campese says the Bati five-eighth isn't even playing at "50 per cent" despite being a shining light during Fiji's surge to the World Cup quarter-finals.

Hayne has been linked with a return back to the Eels as he considers whether to ask for a release from his rich $1.2 million deal with the Gold Coast Titans.

The move would open the door for Hayne to return to Parramatta but he would need to take a hefty pay cut with the Eels only prepared to offer him about half the amount of his current contract for a one-year deal.

Questions linger over Hayne's desire and Campese believes he isn't "giving it his all", but Brown says any club would be lucky to land the signature of the two-time Dally M medallist.

"He'd be a handy addition to any team. He's one of the best athletes in Australia and wherever he goes he's going to be a class act so if he comes, we'll see what happens," Brown said.

"Who knows what's going on there. He's a class player but who knows what happens in that regard."

Campese says "it's pretty hard to contain" a flying Fijian side with Hayne pulling the strings but thinks we're yet to see the best of the 29-year-old in the tournament.

Hayne's status as a game-breaker cannot be denied but he had arguably his quietest game of the tournament in a 38-10 Italy as the game hung in the balance for the best part of 60 minutes.

Campese says Hayne showed some promise in key moments but still doesn't believe he was playing to his potential at Canberra Stadium on Friday night.

"I don't even think he's been at 50 per cent yet to be honest," Campese said.

"He hadn't been tackled before [Friday]. He hadn't played the ball in this comp before [Friday] and you saw in the second half when the game was on the line, he showed a little bit but I still don't think he's giving it his all.

"[Fiji] are going to be one of the teams to watch, definitely... They're probably the best attacking side in the World Cup so far.

"If they can throw that ball around, obviously it was wet condiitons [on Friday night], they're bloody hard to stop aren't they?"

Hayne was sin-binned in Fiji's crushing win following an ugly first half melee and a verbal stoush with Italy hooker Joe Tramontana threatened to boil over on the way to the change rooms.

Tramontana jabbed Fijian winger Suliasi Vunivalu in the ribs while he was on the ground, sparking a scuffle that held up play for several minutes as an outraged Hayne rushed to the aid of his teammate.

The sin-binning left Fijian coach Mick Potter baffled but he won't be losing any sleep over it ahead of a stern quarter-final test.

"I wasn't sure what the ruling was for the other guy as well, it seemed a bit strange and that was when the game was getting heated up a little bit," Potter said.

"I'm not sure whether that was warranted, but again someone else went, then Jarryd went and it was still even stevens. I'm not too bothered about it and I'm not really going to lose any sleep over it.

"We need to get better. [Friday] wasn't good enough, not to beat Tonga or New Zealand, we need to be better next week."