MELBOURNE (Reuters) - Sonny Bill Williams says he will focus on becoming a champion boxer after conceding his body can no longer stand up to the rigours of rugby league.
Williams, who won two rugby union World Cups for New Zealand in 2011 and 2015, has dabbled in boxing since a first professional bout in 2009 but the 35-year-old plans to get more serious about it after building a gym in southern Sydney.
