Sir Alex Ferguson has told BBC Sport that he will never take on fellow manager Jose Mourinho at mind games.
The duo will come face to face again on Wednesday when Ferguson's Manchester United meet Mourinho's Real Madrid in a Champions League tie at the Bernabeu.
Ferguson told Football Focus that his former Chelsea rival "plays games too; he is brilliant at it".
He added: "You are never quite sure what he is up to. I don't go down that road. I let him get on with it."
Following their clash in the Spanish capital, Real will visit Old Trafford for the return on Tuesday, 5 March.
Ferguson is relishing taking on Mourinho again but admits his United side, who top the Premier League table by nine points, face a stiff test.
"I've got to make sure I pick the right team, that's the biggest challenge," said the Scot, who guided United to Champions League titles in 1999 and 2008.
In contrast to United, Real are struggling in their domestic league, lying third in La Liga, 16 points adrift of leaders Barcelona.
But in Mourinho, who has won the Champions League with Porto and Inter Milan, and United old boy Cristiano Ronaldo, they are capable of causing United real problems.
Ferguson says he is aware of Madrid's "obvious strengths" and admits it will be especially tough to win in Madrid.
"They don't lose many games at the Bernabeu," he said. "The atmosphere will be absolutely fantastic."