I assume it's just not that uncommon for Africans to call someone who has been hugely important to them in their lives dad? It does sound weird to me too, but I'm just going to guess it's a cultural difference, doubt he tucks their beds.. At least not every day of the week, he wouldn't have time for that! Bonding with your team can be very important though, there's obviously different approaches and both can work, but for Mourinho it seems important that players can come to him and get help, even if he's having a power struggle in Madrid right now.