Koeman has been publicly critical of his Everton squad, and has suggested that doesn’t have the players required at Goodison Park to implement his favoured high-pressing style.
And Dunne feels that Koeman’s criticism may have created some ill-feeling in the squad at Goodison Park.
“The manager has not been shy in telling them what he thinks of them,” the former Everton defender said. “He wants to replace half the team. There seems to be a division between the players and the manager at the moment.”
Everton have won just once in their last 10 matches, and they have slipped down to ninth in the Premier League table.
The Toffees were beaten 3-2 by Watford at Vicarage Road in their latest outing, and the defeat has caused great frustration around the Merseyside club.
Everton had made a hugely encouraging start to the campaign, but there are now concerns forming about what direction their season is heading in.
Everton are next in action against Arsenal on Tuesday evening, and a victory would go some way to relieve the pressure building on Koeman.