There’s likely to be a shake up in the Prix de l’Arc de Triomphe betting this weekend with key trials on both sides of the English Channel.Longchamp hosts the most significant prep races for Europe’s greatest 1m4f race, while Kempton’s September Stakes is in danger of becoming a circus side show with former top hurdler Constitution River taking on Arc possibles Bay City Roller and Gethin.In France, all eyes will be on Daryz in the Prix Foy at Longchamp as he warms up for the defence of his crown at the Paris track next month but it might well be a stablemate that sends her Arc odds tumbling on Sunday.SUNLY is likely to line up in the Prix Vermeille having finished a close third behind top-class Calandagan in a Saint-Cloud Group 1 in July.‌Francis-Henri Graffard’s filly had chased home Aventure – runner-up in the 2024 Arc – at Longchamp in May over a trip short of her best.She will have just her eighth run this weekend and she seems to be improving all the time. A stiff test of stamina over1m4f will bring out the best of her and she is likely to get that set-up in the Arc.If she passes this weekend’s trial, then she will be an awful lot shorter that the 50-1 currently on offer with William Hill (33-1 generally).Fillies have won nine of the last 15 Arcs and Sunly might just be another.‌Trainer HotDave EvansHe might not have the number of horses that twice saw him pass a hundred winners of the season but the Welsh trainer has his team in sparkling form.Backing his runners over the last fortnight would have a returned a profit of 10.5 to level stakes, despite several runners hitting the crossbar.‌Musashi is an interesting recruit from Joseph O’Brien and he makes his debut for the stable at Salisbury (1.53) tomorrow.Trainer NotDavid MenuisierIt’s been a barren summer for the Sussex-based Frenchman.‌His last winner was way back on June 30 and he had just three horses placed from 21 runners in August.It points to problems as there is always a reason when good trainers go through dry spells. When his team turn the corner he will have well some well handicapped horses on his hands but that might mean waiting until next season.