Ratcliffe believes Koeman needs to win over his players.
He told the Mirror: “Sometimes he comes over as being quite arrogant, which doesn't go down well in the dressing room.
“I think it's hard to give Koeman advice. He was a top player at Barcelona, some of that coming from being mentally strong.
“And he has brought some of that into his management. It doesn't matter what you say – he is right. He needs to sit back and reassess everything."