Rather than feeling the need to prove a point to Hammett, Weepu said it was more about proving a point to himself.
"It's my old franchise and the toughest decision was to leave there but I've just got to do my best to go out there and get my team the win. He [Hammett] is down there and taking control of his team and obviously he's made a pretty good start to the campaign with the team that he's got."
Nonu, meanwhile, said moving was professional sport.
"[Peyton] Manning has been traded to the Broncos [in the NFL], David Beckham left Manchester United and went to Real Madrid so - I'm not like those guys - but these things happen."
Nonu, who made his Super Rugby debut for the Hurricanes in 2003, said he was unsure how he would feel lining up against his old mates but one in particular - former centre partner Conrad Smith - will be keeping him busy.
"I've played him at club footy - they won that game from what I remember. He's pretty slippery, they don't call him Snakey for nothing. Obviously he's the captain as well and he's playing good footy."
Making his first appearance for the Blues this season is loosehead prop Tony Woodcock, who will do well to keep Hurricanes hooker Dane Coles in check after his vigorous display against the Highlanders last weekend.
Coles escaped sanction despite a borderline ruck clean-out and also a punch aimed at reserve prop Bronson Murray, whereas Blues flanker Luke Braid has been suspended for three weeks for striking a Stormers player, a situation which has annoyed coach Pat Lam.
Woodcock's return comes as the Blues are reeling from the serious injuries to Isaia Toeava and Jerome Kaino, plus problems with Keven Mealamu, Anthony Boric and George Moala. Wing Rene Ranger is serving the second week of a two-game ban.
Woodcock has played one match for the Blues Development team as a build-up. "I'm just keen to get back into it," he said.
His elbow and foot problems now felt 100 per cent due to his extra rest, he said.