At 34, the Swede left PSG for United.
Vieira said: “When a move to Manchester United came up, he came to me for advice.
“I told him it wouldn't be easy, that it was going to be a challenge. Then again Zlatan has never made life easy for himself."
LA Galaxy star Ibrahimovic says in his latest book that Vieira “made me a better player and he had the work rate of a horse".
He claims the former Gunners enforcer had “the biggest influence" on his game.