Tomas Berdych and Roger Federer pose for a photo with young tennis fans after a training session ahead of the Laver Cup on September 20, 2017 in Prague, Czech Republic. The Laver Cup consists of six European players competing against their counterparts from the rest of the World. Europe will be captained by Bjorn Borg and John McEnroe will captain the Rest of the World team. The event runs from 22-24 September.