Brazil head coach Dunga has labelled Chelsea midfielder Willian as one of the keys to his tactical revolution alongside Neymar as the Selecao prepare to face Chile at the Emirates Stadium on Sunday. The five-time World Cup winners trained on the pitch of Arsenal's 60,000-capacity ground on Saturday ahead of the sell-out South American showdown in London on Sunday. And with just over two months until the Copa America begins, Dunga - appointed head coach in the post-mortem of Brazil's embarassing World Cup elimination - sees Willian and Neymar as two of the key men in his tactical revolution. Thiago Silva, Miranda and Neymar (L-R) are at the centre of the laughs as the Brazilians enjoy training . Real Madrid defender Marcelo (left) leads his team-mates into a huddle for a photo at the Emirates Stadium . Neymar (left) laughs during a conversation with Chelsea midfielder Willian (third left) during a brief break . Neither player started in the 7-1 humiliation against Germany in last year's semi-final, and Dunga wants the movement and mobility the pair share to help redefine the way Brazil play in the hope of bouncing back from their last tournament appearance. 'The movement and mobility of our players is key,' Dunga said. 'The more they play together the more things become automatic. 'Willian is skilled. He has a lot of pace, a speed in his reasoning and he can make the difference in many games. Neymar is doing very well and will only grow.' 'In regard to goals I don't think that will be a problem. But the record we really want him to get is Pele's number of World Cup wins.' Brazil head coach Dunga talked up the abilities of Neymar and Willian as two of his star players . Willian has grown into an increasingly important figure for Brazil since last summer's World Cup disaster . Marcelo, Neymar and Luis Adriano (L-R) are all expected to be involved in Sunday's friendly in London . Both Neymar and Willian are set to be key men in Dunga's side for this summer's Copa America, where he has confirmed that no new players will be brought into his squad. 'Those who have never been called (for the squad) are not out, but they will have to wait for another opportunity,' he said. 'The Copa America is a competition, where we have to put players who already have an answer. The Copa America is not the place to test a player. I can't select someone I haven't worked with.' Barclays Premier League pair Philippe Coutinho and Oscar put themselves about during the training session . Neymar has been getting used to the Emirates pitch as he looks to further his impressive international record . Brazil have no new injury problems though Dunga said he will make changes to his side in London. David Luiz and striker Diego Tardelli are both missing again but London fans will see plenty of familiar faces including Chelsea trio Oscar, Willian and Filipe Luis. Brazil defender Gabriel Paulista could be up against his Arsenal team-mate Alexis Sanchez at their usual home. Coutinho gestures during a game as Chelsea's Filipe Luis (left) looks on during Saturday's session . Dunga has no new injury problems to deal with ahead of the Chile clash in a World Cup second-round repeat .
Brazil face Chile at the Emirates Stadium in a friendly on Sunday . Neymar, Thiago Silva and Oscar have been training at Arsenal's stadium . Brazil head coach Dunga says Neymar and Willian are key to his side . He praises the attacking pair's ability to create opportunities in movement .