And the Italian chief has made the stunning claim that the Blues have agreed to pay the teenager an astonishing ?870,000-per-year to move to west London.
Piazon - who has been dubbed the 'new Kaka' - is set to join the Barclays Premier League champions from Sao Paulo once he turns 18 in January 2012, in a deal that could rise to ?8million.
On the up: Lucas Piazon is certain to make a move to Europe when he turns 18 in 2012
But at one stage, Piazon looked set for a move to Turin with some reports even suggesting a deal was already in place for the Brazil Under-17 star to become a Juventus player.
Chelsea feel they have acquired one of the hottest properties in world football - but Juve chief Marotta has attacked the Stamford Bridge club for using huge amounts of money to lure the talented attacking midfielder.
Marotta said: 'We're actually proud that we haven't signed Piazon under these conditions. It would have been unethical to pay a minor a salary in the region of €1million (Euros).
'What would his future team-mates be thinking? Players who have yet to sign a professional contract.
'It's hypocritical to argue that players earn too much money nowadays and then criticise our decision not to meet Piazon's demands.' Marotta's criticism is the latest in a growing line of attacks on Chelsea's quest to lure the globe's brightest talent to the club.
As reported in Sportsmail last December, Feyenoord sporting director Leo Beenhakker pointed an accusing finger at Chelsea for their pursuit of 15-year-old defender Nathan Ake.
He said: 'It's driving me crazy that hot prospects are walking away from us like this. The Premier League clubs spoil the market with their behaviour. Other clubs in Europe don't behave like this but the English sides just don't care.'
Despite the pending arrival of Piazon and the recent big money signings of Fernando Torres and David Luiz, Chelsea chief executive Ron Gourlay last night insisted that promoting players through the club's academy remains a top priority.
Making a point: Carlo Ancelotti remains under pressure to bring youngsters through the academy at Chelsea
He said: 'The strategy of the club hasn't changed, it was always the intention to get the young guys through and develop the academy.
'Unfortunately we hit a period where we lost our form and Carlo decided he wanted to play with experience. We needed to get the young guys out on loan.
'I said at the start of the season that if we needed to buy to compete, we're not going to go in any bidding wars but if the right players become available then of course we're in a position to go into the market.
'We proved that with Fernando and Luiz and they've both been fantastic signings.'
Chelsea last night declined to comment directly on Marotta's comments.
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