There is not much news on this subject, but the team he leads is fully supportive and will welcome him back when he is better. For now, he will be replaced by Jarno Mensonen, who will obviously act as interim head coach.
His son Jesperi will certainly take care of him since the health of a loved one is more important than hockey. However, knowing a bit about the father's philosophy, Kotkaniemi will definitely be pushed by "dad" to not neglect anything in his summer training.