Johan has been an excellent servant to Celtic as a player and, for the last few years, as part of the backroom team alongside manager Neil Lennon.
He has enjoyed a lot of success at Parkhead in both of his roles, but it has been confirmed that he will move on and seek fresh challenges away from the club next season.
It was Johan that Neil turned to when he was given the chance to manage Celtic and I am sure he will be disappointed to see him leave but, like everyone at the club, he will wish him well for the future.
They have enjoyed a lot of highs together as they have taken Celtic to league titles, cups and had some wonderful nights in the Champions League.
But Johan obviously feels the time is right to have a go at other things and has decided that now, with three-in-a-row secured, is the time to leave.
Although the news about Johan's departure emerged this week, Neil would have known for some time what was going to happen and it is now up to him to find a suitable replacement and bring someone into that role before the new campaign.
There are a number of reasons why Johan could want to leave. Maybe it is for family reasons or maybe he would like to have a go at being a manager in his own right.
Neil and Johan have had a lot of success as a management team and carried on where they left off when they finished their playing careers at Parkhead.
They clearly work well together and it will be a blow for Neil to see someone he has worked so closely with leave the club.
We are nearly at the end of the season and the attention will soon turn to bringing in players and the Champions League qualifiers, which, as we know, is so important to Celtic on and off the park. Having to find a new assistant manager is another job for Neil to add to his to-do list over the summer, but I am sure he will take his time and make the right appointment.
He will want to get it done sooner rather than later but it is important that the right man comes in.
It will be interesting to see who he opts to bring on board but I don't think there will be a shortage of people interested in taking up the position.
Neil may decide to promote from within the club, Garry Parker could step up from his role as first- team coach or someone like John Kennedy could be promoted from the youth set-up.
He might look to bring in someone else and bring a fresh face to the staff at Parkhead. The biggest thing when making the appointment is that it has to be someone that Neil can trust, that is so important.
A manager has to be able to trust his assistant. It is a team effort and the manager has to be able to talk to his assistant and turn to him for advice.
It does help that you share a similar outlook on the game in terms of how it is played and the players you want in the team and want to bring in.
But trust is the main quality Neil will look for and I am sure he will already have people in mind for the position and he might even go for another of his former team-mates.
I don't think it is a neccesity that whoever gets the job has a previous history with Celtic.
It may help whoever it is settle into the job but I don't think it is compulsory and I don't think Neil will necessarily be thinking along those lines either.
He brought in Garry Parker who, although he was a long-time friend and former team-mate, had no previous affiliation with Celtic and he has been part of the backroom team for a while now.
As I said, everyone will wish Johan well in the next stage of his career but now it is up to Neil to make the transition as smooth as possible for next season.