"He has a very nice lifestyle. I don't see why he doesn't see his career out at Madrid, probably," Jonathan Barnett told BBC Radio 4's "Today."
Barnett added: "As I've always said, he's quite happy in Madrid. It's his life that he wants to lead. Financially, he will want for nothing the rest of his life, and his children and grandchildren.
"He's won nearly everything in the world, except the World Cup, but unfortunately he plays for Wales so some things are beyond him. So he's won everything else, to come back and play (in the Premier League) would be unbelievable, a big thing.
"I don't think he wants to do that at the moment. He's quite happy to play at Real Madrid."
Bale nearly left Madrid last summer after a bitter dispute with Zidane, who publicly called on the 30-year-old to find another club. Bale was reportedly set to join Chinese side Jiangsu Suning on a three-year contract worth over £1 million per week, but Madrid nixed the deal at the last minute. He was also linked with a move to Manchester United.
Zidane appeared to make amends, starting Bale in six of Madrid's opening eight matches of the 2019-20 La Liga season, but a calf injury interrupted the winger's run of form.
Bale joined Madrid from Tottenham Hotspur in 2013 for a then-world-record £85-million fee. He's won the Champions League four times with the club and scored more than 100 goals during his time in Spain.
His contract with the 13-time European champions expires in June 2022.