Makitorix has run just once since arriving from France, scoring by 18 lengths on his hurdling debut at Listowel in September, and Mullins is unsure what to expect.
He said: "We had a couple of other horses that we thought might run in the race, but through one thing and another they don't and Makitorix has come to the fore.
"He will lack a bit of experience, but we'll take our chance and we'll know what we have on Sunday."
Gordon Elliott is triple-handed in his bid to win the Royal Bond for the first time.
Heading the team is*Mengli Khan, who having been beaten over hurdles twice last season, has raised his game to register two impressive victories at Navan this term.
"Mengli Khan is a different horse this year," Elliott told At The Races.
"He was a big shell last year and he's a lot stronger now.
"I'd say it was the best thing that happened that he didn't win a race (last season)."
The Cullentra handler also saddles*Hardline and Morgan.
The seven-strong field is completed by the JP McManus-owned trio of Early Doors,*Le Richebourg and Red Jack.
Early Doors and*Le Richebourg are both unbeaten over hurdles for Joseph O'Brien, with the owner's retained rider Barry Geraghty siding with the latter.
Red Jack*has won two bumpers and a Naas maiden hurdle for Noel Meade and tests his powers at the highest level under Sean Flanagan.
Meade said: "Red Jack is 100 per cent.*He's done everything right since Naas and everything has gone right. We've had no setbacks, he's schooled well and everything has gone well.
"He'd want to step up a long way from Naas. It's a huge race and a very hot field, but he'll take his chance."
