Frenkie de Jong says Barcelona told him to knock Real Madrid out of the Champions League when sealing his move to the LaLiga champions.
The 21-year-old has agreed to join Barcelona in the summer, deciding against moves to Manchester City and Paris Saint-Germain to agree a transfer worth up to £75 million.
Ajax lost 2-1 at home in a controversial first leg as they look to become the first team since Juventus in 2015 to eliminate Real Madrid from the competition.
"I spoke to them when I signed the contract and they told me to try to knock out Real Madrid, as that would be great for Barca too," De Jong told Dutch newspaper De Telegraaf.
Ajax's daunting task of turning the tie around has been given a slight boost by the suspension of Real captain Sergio Ramos, who picked up a yellow card late in the game in Amsterdam.
De Jong urged his side to be courageous and believes they can still cause a shock by eliminating Madrid, who have lost their last three games at the Bernabeu and were beaten 1-0 and 3-0 by Barcelona in their previous games.
"We have to play on the attack, put them under pressure and play great football," he added.
"If everyone contributes, we have enough quality to cause a surprise."
Additional reporting by Reuters.
