Serena Williams tweets John McEnore after his ranking remark

John McEnroe's belief that Serena Williams would be ranked as low as 700 in the world if she played on the men's tour has drawn short shrift from the 23-time women's singles grand slam champion.

Williams' major haul is a record for any tennis player - male or female - in the Open era, but McEnroe courted controversy by suggesting the 35-year-old would struggle on the ATP Tour.