Who said that? When you say some people, you obviously saw someone say it, please specify or else no one would take you seriously, not that anyone does anyway.
I am against the fasting but I think that a Muslim football player can do without fasting if it is in the way of training and matches. Then again my biggest reason for me not wanting Sissoko is because of his tendency to do numerous amounts of turnovers every match, fasting is a minor issue. Even if a Christian player or an atheist that decides to fast during the season, I would be against it.
I mean a DM who is capable of retrieving possession back. A player who is able to make simple passes and spread play.
This doesn't entirely concern Sissoko only. I'm just stating that a formation without a DM against a top team can prove to be badly. Melo is a good example of what do I expect from a DM.