The French-based jockey knows the Emmanuel Clayeux-trained 10-year-old better than anyone, and gave him a splendid ride when the partnership claimed victory at the track in January 2017.
This will be Urgent De Gregaine's first appearance at the Festival, but hopes in the camp are high that he can improve upon a third-place finish in a handicap over the banks course at Cheltenham in November.
De Giles said: "Emmanuel has two in the cross-country race (the other being Vicomte Du Seuil), but I'll be riding Urgent De Gregaine.
"He's in really good form and enjoyed a racecourse gallop the other day. He was close to coming over last season for the Festival, but we decided against it as he wasn't quite 100 per cent.
"He's in great order this year, though, and I think he's definitely going there with a competitive chance."
De Giles is unlikely to be recruited by any domestic trainers at the Festival, but he is cautiously optimistic about the chances of fellow French challenger Brave Dancing in the Fred Winter.
The jockey said: "He'll be having his first run for David Cottin and won at Pau in February.
"He's very well and is a strong horse, but I don't think the handicapper has done him any favours.
"I imagine he's not a well-handicapped horse, but he might be a horse that acts well at the track."
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