The steroid case involving top-ranked tennis player Jannik Sinner was appealed by the World Anti-Doping Agency, the Montreal-based body announced Saturday. WADA said it is seeking a ban of one to two years for the U.S. Open champion but indicated that it does not plan to back date an eventual ban — which would mean that Sinner could keep his second Grand Slam title if he is found guilty. The announcement was made while Sinner was on court against Roman Safiullin at the China Open in Beijing.