Ronald told the radio station: “I'm 90% [certain] he will stay at Ajax. It all depends on what what club is going to come and ask him [to manage them].
"He doesn’t have to go though, he’s very happy at Ajax."
It certainly makes a change from the recent quotes heard from Frank, as a lot of the time he has been quoted in the media he has been talking about jobs away from the four-time European Champions.
De Boer said in the summer that he would have taken over the reins as Tottenham Hotspur Head Coach if they hadn't have opted for Mauricio Pochettino at White Hart Lane. De Boer had publicly revealed an interest in swapping Amsterdam for North London.
Then there were links with him taking over at Anfield when they were searching for a successor to Kenny Dalglish when the club legend was sacked from his post in the summer of 2012. He explained it was because of a new contract he had just signed in an interview with Sky Sports, and Liverpool opted for Brendan Rodgers.
Frank also had this to say about where he would like to manage in the future, along with speculation linking him with a move to Newcastle United immediately after the departure of Alan Pardew.
"I would like to manage in England but also Germany and the Spanish league because they are the three best leagues in the world, so I would like to get that experience.
"I have everything open... but I will be ready, that's for sure."
One would have to ask that if he is so happy managing Ajax, why has he been declaring his interest to manage other clubs? It is a bit of an odd stance to take and not one that will go down well with the club's fans, you'd think.
While his brother claims he is happy in his current position, it does strike as a little contradictory.