Christophe Soumillon will be reunited with the Aga Khan's Tarnawa (Ire) (Shamardal) in the G1 Prix de l'Arc de Triomphe on Oct. 3. Soumillon, the Aga Khan's retained rider in France, was aboard Tarnawa for wins in last year's G1 Prix Vermeille and G1 Prix de l'Opera, but was replaced last minute by Colin Keane for Tarnawa's victory in the GI Breeders' Cup Turf at Keeneland after testing positive for Covid-19. Keane was in the saddle for Tarnawa's comeback score in the G3 Ballyroan S. on Aug. 5 and for...