The Pocket Rocket is, though, still looking to overcome a hamstring strain with Dale Rasmussen (knee) and Calum MacRae (broken thumb) also out injured.
However, Ruddock is confident he has quality options open to him if Tuitupou fails to make the big opener in front of the television cameras.
"We are confident that we can get a very talented centre partnership out there," said Ruddock. "We have a fitness test on Sam coming up, it could be a little too early but we will see how he pulls up.
"If there is any doubt we won't risk him because we have a short turnaround before we face Leeds the week after.
"People will say we were short in the centres last year when we picked up injuries, but Alex Grove came in and look how he did. Whoever we pick we know they will be up for the challenge and go well for us.
"We have the option of Rico Gear and also Greg King, who played against Ulster and did very well and did well when he came on against Bourgoin last year.
"Greg is a youngster who is looking to establish himself like Alex Grove did, if that happens I am sure he will do well."
One absentee from Franklin's Gardens will be Kai Horstmann who is looking to overcome a rib injury.
"Kai looks like he's not going to make this weekend's game," added Ruddock. "He's still carrying over a rib injury from the end of last season.
"He's had a problem with the bone healing in the right way, so that might take another week or two before we see him back."