American runners John's Call, Timboroa, Euchre, and Lord Sterling had their first serious exercise at Tokyo race course on Thursday in preparation for the Japan Racing Association's two major group I international races: the inaugural $2.4 million Japan Cup Dirt at 1 5/16 miles on Saturday and the $4.4 million Japan Cup run at a mile and a half over the turf on Sunday.John's Call and Timboroa teamed up to work an easy half-mile on turf, with exercise rider Jose Cuevas up on John's Call for trainer Tom Voss, and David Flores riding Timboroa for Bobby Frankel. They were clocked in 52.2 seconds with a final eighth in :12.8. "We just let him stretch his legs a little and give him a blow," Voss said of the 9-year-old Lord at War gelding who's won two grade I races this year and finished a close third in the Breeders' Cup Turf (gr. IT). "He's doing very well." Frankel had looked for a slightly quicker time from Timboroa, who won the Carleton F. Burke Handicap (gr. III) in his third U.S. start. "It was fine, though," Frankel said. "What happens in the morning isn't nearly as important as what happens in the afternoon."Later in the day when post positions were announced, John's Call drew the No. 12, with Timboroa getting 7. Japanese star T.M. Opera O, winner of six stakes in Japan this year, will be the heavy favorite in a field of 16 runners.Among the five Europeans entered in the Japan Cup is Godolphin's Fantastic Light, the Man o' War Stakes (gr. IT) winner who ran fifth in the Breeders' Cup Turf. He was clocked seven furlongs in 1:28.6 on Thursday. Another European is the filly Ela Athena, who finished third to John's Call in the Turf Classic (gr. IT) and second to Fantastic Light in the Man o' War. She worked three furlongs in :39.5. Also working easily was Italian and German group I winner Golden Snake and group I-winning French filly Reve d'Oscar.Euchre and Lord Sterling are the only non-Japanese horses among 16 going in the Japan Cup Dirt. Each worked on the dirt track, the speedy Lord Sterling clocked three furlongs in :36.5 and Euchre a half-mile in :50.2. Lord Sterling will carry the hopes of Californians Ron and Susie Anson, whose silks, adorned with the Chicago Cubs logo, are becoming very familiar to California racegoers. Lord Sterling was a $50,000 claim by the Ansons, and the Black Tie Affair gelding has climbed the ladder out of the claiming ranks, with his most recent performance a strong second in the Meadowlands Cup (gr. II). Jose Valdivia Jr., who will ride Lord Sterling for trainer Alfred Marquez, was not aboard for the workout, but he walked the dirt course and described it as "sandy like the Del Mar beach," but with a firm bottom.Euchre, scratched from the Breeders' Cup Classic (gr. I) by Frankel after coughing the morning before the race, exits a strong third-place showing behind Tiznow and Captain Steve in the Goodwood Breeders' Cup Handicap (gr. II). Flores was aboard for Thursday's work and will ride the Personal Flag gelding for owner Frank Stronach on Saturday. "He's not a speed horse," Frankel said of Euchre, "but he needs an aggressive rider. If you let him settle too much in a race, he'll get lazy on you. He needs to be ridden all the way -- not hard, but you have to stay after him."Euchre is expected to be favored in the race. He drew the seven post with Lord Sterling drawing 5. The top Japanese hope is Fast Friend.