Everton have won just once in their last 11 matches in all competitions.
Everton fans let the team know about their anger, after the Toffees fell to a 3-2 defeat against Watford in their latest outing.
The Toffees have now won just once in their last eight matches, and they have slipped down to ninth in the Premier League table.
And Koeman said, of Everton fans’ reaction to their latest defeat against Watford: “I understand, because they are frustrated.
“They are frustrated because it is really a bad run in the last 10 games.
“But we go on. We need belief, and the reaction of the fans is one I can understand. We need to change that reaction, and I hope we can give them a different feeling on Tuesday.”
Everton actually had taken the lead against Watford when Romelu Lukaku tucked home early on.
However, they were unable to hold on and the Hornets went into a 3-1 lead.
Lukaku did pull a goal back for Everton, but it was not enough, as Koeman’s side fell to another disappointing defeat.
The Toffees are next in action against Arsenal at Goodison Park on Tuesday evening, when the pressure will be on them to collect a positive result.