Ajax midfielder Kenneth Perez admits he was surprised by the acquisition of Ismail Aissati from PSV Eindhoven.

The 19-year-old Aissati penned a four-year contract at the Amsterdam ArenA on Monday morning and has been handed the number 11 shirt by new coach Marco van Basten, with 33-year-old Dane Perez given the number 21.

"That is not a very promising number," Perez told AD Sportwereld.

"I thought Ajax was looking for defenders. Ajax now have a lot of attacking midfielders."

Perez is prepared to battle for his place in the team, though, and hopes his versatility will aid his cause.

"I don't know what the coach wants with me," he said. "That will become clear in the coming weeks. I focus on the position behind the central striker, but I can of course also play on the left."