Van Gaal will leave his post as Netherlands coach after the FIFA World Cup and is expected to be confirmed as the replacement for David Moyes this week.
Giggs has taken interim control since Moyes' departure last month and will face Bruce at Old Trafford in his third game in charge on Tuesday.
Bruce spent nearly nine years with United as a player and won three Premier League titles with Giggs under the guidance of Alex Ferguson.
And the 53-year-old feels that the Welshman could play a pivotal role in helping Van Gaal succeed with United.
"There's always going to be a place for Ryan at United because he has been a great there," Bruce said.
"But it's a difficult one to call because if it is Van Gaal, he will have his own opinions on it. But I'm sure they will find a space for Ryan somewhere.
"He'll do something and I don't think he'll leave. He will be treated properly, I'm convinced of that, and he will have some role to play.
"Ryan may still have a role as a player. If Ryan feels up to it, why wouldn't you keep him on?
"I saw him play a few weeks ago, and he still looks a very good player to me.
"If he was to be available on a free this summer, I'd take him. He can come and see out his days at the KC (Stadium) in the Europa League."
