Angel Di Maria says Real Madrid sold him to Manchester United to cover their costs after signing James Rodriguez and Toni Kroos last summer.
The Argentine, now at Paris Saint-Germain, was signed by Louis van Gaal for a British-record £59.7m, but struggled at Old Trafford before a £44.3m sale this summer.
Di Maria returned to the Bernabeu on Tuesday night with PSG, suffering a 1-0 defeat in the Champions League group stage, and opened up about the manner of his departure in the summer of 2014.
"I didn't leave for money," Di Maria told reporters after PSG's defeat on Tuesday night.
"I wanted to see if I could renew and they didn't want me to. They wanted to cover the costs of the great players they had signed that summer.
"I had to leave by the back door. It wasn't how I would have wanted."
Di Maria has scored four times in his 12 appearances for the French champions this season, and insists he is settled in Paris and wants to stay for "many years".
"I am changing little by little," he added. "I'm happy in Paris and I hope to be for many years."