Despite last season's run to the Champions League semis, Ten Hag says Chelsea are the superior team.
Ten Hag said: "Last season is the past. We must forget it and think about the future and what we are doing now.
"Chelsea is a different team as with the coach as well as in performance.
"We are not favourites against Chelsea. They resemble us because they have the same philosophy of play, they want to keep the ball and press high in the non-possession phase. The field after the Amsterdam Music Festival? It will hold, I'm sure. They all worked hard so that the game could be played without problems."