Mullins said: “I thought he (GDC) ran a cracker as he probably needed the race against that type of opposition.
“He looked like he might win after the second-last and again going to the last, but the lack of a race told on him in a race of that calibre over that trip.
“I’m hoping he’ll improve, you never know. He did have a hard race and you don’t know what sort of effect it will have on them, but he went home and ate up, which is a great sign. It suggests he didn’t take it as hard as I thought it looked.
“Hopefully he’ll be back for the Irish Gold Cup.”
Galopin Des Champs is a 6-1 joint-favourite alongside the defending champion Inothewayurthinkin for the Cheltenham Gold Cup with Paddy Power, with his stablemate Gaelic Warrior a 10-1 shot after he was beaten a short head into third place in the King George VI Chase on Boxing Day.
Of the latter, Mullins added: “He ran a cracker in Kempton. Things didn’t fall for him and he met a bit of traffic.
“Fact To File was a bit disappointing, he probably just didn’t handle the track and it was a slowly-run race. They have both come home OK.
“Gaelic Warrior could come back here (Leopardstown) for the Irish Gold Cup, it could be a fascinating race.”