Ajax coach Erik ten Hag admits he must change their style of play after losing Hakim Ziyech.
The midfielder was sold by Ajax last season to Chelsea for a fee rising to €44m.
And Ten Hag admits the loss of Ziyech will impact of their system, stating: "When you lose players who have had a great influence on the game, the style of play changes.
"You lack certain qualities, but of course the intentions are the same. One always tries to set the bar higher than last season. The challenge is to get more out of the players who are here now.
"We have a strong composition of players. We have two men for each position, except for the left back. We have to see if we can find a solution internally, and otherwise we have to look externally."
