Men's No.1 Jannik Sinner has refused to rule out a boycott of tennis' Grand Slam events as the sport faces an ugly civil war. Sinner, 24, believes that players aren't getting the respect they deserve amid a dispute over prize money. The Italian has followed women's counterpart Aryna Sabalenka , who this week warned tennis chiefs that stars could skip majors 'at some point' . The top 10 players from both the men's and women's games issued a joint statement on Monday demanding a higher percentage