A SILVER medallist in the 400m at the Delhi Commonwealth Games, Sean Wroe faces a huge task off scratch in this weekend’s Black Opal 400m at the Bendigo International Madison carnival.Wroe will race off scratch in the first of six heats in the Bendigo Bank-backed classic on Saturday afternoon at the Tom Flood Sports Centre.The Black Opal is the richest 400m in the country.Wroe was a finalist in Bendigo’s 400m showdown on a waterlogged track a year ago and went on to win gold in the 4 x 400m relay in Delhi.The Black Opal was won by AFL boundary umpire Adam Coote.In Saturday’s heats, Wroe will concede 15m to his nearest opponent, Canberra’s Tom Burbidge. Limit marker in heat one is Tullamarine’s Nick Howard on 40m.Wroe’s rivals in heat one include Eaglehawk’s Glenn Stephens off 32m.Stephens is a previous Black Opal winner and won the Bendigo Thousand 120m sprint on his home track.Contenders for the Black Opal include Andrew Boudrie (10), Daniel Steinhauser (11m), Lachlan Taylor (12)Alex Rowe (16), Cam Dunbar (21) and David Tinney (22).The 2010 Black Opal winner, Adam Coote wlll race off 20m in heat six.Coote will contest the City of Greater Bendigo Thousand 120m sprint.Heats start about 3pm.Coote will start on the 9.75m mark in the second of nine heats.Bendigo-based sprinters chasing victory in the Thousand are David Morrissey off 7.25m in heat two, and Glenn Stephens from 12m in the seventh heat.Athletic events at the two-day Bendigo International Madison include the open 70m, women’s 120m, women’s-veterans 800m, open 800m, novice 400m, women’s 400m, frontmarkers and backmarkers 1600m finals.