In an interview with the 'Liverpool Echo' Koeman has said that the £24m summer signing is more than capable of adjuting to the rigours of Premier League life.
"Davy has made this step in his career at the right time," said Koeman.
"He spent four seasons with Ajax and gained experiences in Europe and with the Dutch team."
The former Southampton boss did admit that Klaassen would need to adapt but insisted that he had both the intelligence and the ability to do so.
"He will have to get used to the high tempo we play and it will tougher for him, especially from a physical point of view, but Davy has developed well as a player. He is intelligent and can read the game," explained Koeman.
The 24-year-old is expected to make his competitive debut for Everton in their Europa League third qualifying round game against Ruzomberok on Thursday.