It means the 23-year-old, who plays on the wing, will have a chance at making his NRL debut in the second half of next year, or potentially being upgraded to a fulltime deal over the off-season if he impresses coach Wayne Bennett and the rest of the staff during the pre-season training block.
He has played 12 games for the Dolphins at reserve grade level this year, scoring 10 tries in 12 games, to go with 67 tackle busts, 8 line breaks and 156 metres per game.
Samoan born, Tu spent time in the Warriors system before linking up with the Dolphins.
“You always hope something like this will happen, but you are never sure,” Tu said in a club statement announcing thenews.
“I have just been focussing on playing my very best for the Redcliffe Dolphins in the Hostplus Cup and I think that has helped me get this opportunity.
“I can’t wait for November to arrive so I can begin working on my game during an NRL pre-season.”
Tu, who is eligible to play for Samoa at the end of year Rugby League World Cup, but unlikely to be picked in a squad which is almost certain to feature 24 NRL regulars, had to overcome injuries last year to get back on the field this year.
Dolphins' CEO Terry Reader said he has earned his opportunity to train with the NRL squad.
“Setu is a try scorer, he is dangerous in the air, he is good at carrying the ball and can also produce line breaks - in short, he is a really good all-round player,” Reader said.
“We are very glad to be giving another young Redcliffe player a shot at reaching their NRL aspirations with the Dolphins’ NRL team.”