The durable grey belied his odds of 50-1 to take third place behind Roaring Lion 12 months ago, and his trainer believes the six-year-old is ready to turn in another big performance on the Knavesmire on Wednesday.
Thundering Blue has had just the three races this campaign, and Menuisier is happy to ignore his latest run in the Grand Prix de Saint-Cloud – in which he was last of seven behind Coronet – because he was unsuited by the lack of pace.
“His last run you can draw a line through, because it was a typical French race with no pace,” said Menuisier.
“They ran in snatches – stop go, stop go. It wasn’t going to suit him, so I’m more than happy to draw a line through that.”
The Sussex-based Frenchman is confident Thundering Blue will put in a much-improved showing at York.
He added: “I think he’s definitely coming on – he’s a very seasonal horse.
“He comes to himself in the summer, and I’m genuinely very pleased with him.
“He went to Newmarket for a racecourse gallop last weekend, and I was delighted with him. He seems happy and full of beans. I couldn’t be more pleased.”