Koeman is currently under pressure at Goodison Park, with Everton sitting in 16th place in the Premier League table and having failed to win either of their two matches in the group stages of the Europa League.
The North-West outfit had to contend with two qualifying rounds in order to reach the main draw, and Koeman has suggested that their earlier start to the season prevented the players from doing work out on the training pitch.
The 54-year-old told reporters: "I think one reason we struggled is that we didn't really have training sessions and that started in pre-season. We did not have a normal pre-season because we had to play really fast, really competitive to qualify for Europe.
"The schedule is so tough and you don't have time to train or improve, and we didn't have one new player, we had eight or nine new players and that takes time.
"For that reason I'm happy that we play on Sunday [this week] and we can have a normal training session today."
Everton make the long trip to Brighton & Hove Albion this weekend.