Rafael Nadal has called for players to be hit with tougher punishments if they are found to have violated conduct rules after Alexander Zverev was handed a suspended eight-week ban for his on-court outburst in Mexico last month.
Zverev, the world number three, has been allowed to return the court and is set to play in the ATP Masters Series in Indian Wells this week, but any further incidents of unsportsmanlike conduct or verbal abuse will see the ban come into effect.
