The 24-year-old made a £23.6m move from Ajax over the summer and was expected to be a linchpin in Everton's new-look attacking midfield but he has yet to set the Premier League alight.
It's a situation that his new manager Ronald Koeman acknowledged this week when he reaffirmed his belief in the Dutch midfielder while Klaassen himself reflects on his middling start to life in England in this evening's match programme for the game against Apollon Limassol.
Klaassen starts the game on the bench despite being named in the starting XI that faced Bournemouth last Saturday.
"It has not been easy for me to adapt," the Netherlands international explains. "I need to improve."
"[The Premier League] is a different speed to the one I am used to, a different intensity, but that is what I wanted. I wanted something else, something bigger."
"The fans have been great since I arrived... I like it here, the life is similar to Holland... Even the weather is the same... I'm used to the rain back in Holland!
"At the same time, everything within the club is different [to Ajax]. Everything is a little bigger, the pitches are really good and the stadium is really nice.
"Everton is a big club, but it's difficult to compare the two clubs I have played for. They are both big clubs, but I think the biggest difference here is the league. In Holland, not everything is that big but when you come here it is huge.
"Before coming to Everton, I knew the players and the club, but I didn't know how big it was.
" We've had some difficult games," the 24-year-old continues with regard to Everton's rocky start to the 2017-18 season, "and it's even more tough when you sign four, five, six new players. It takes time but we're getting better.
"It's true I cam so close to winning the Europa League last season, but I don't need to lose in a final to be hungry for this campaign. We all want to go as far as possible and I have confidence in this squad."