There can be several reasons like: losing a certain game on purpose, hiding his formation before the games, tanking, etc.

This is clearly something unorthodox but as I said on another thread there are many, many people who do this and Top Eleven can't track them one by one, there's nothing that they can do unless he came and say, yes I did it! Losing on purpose as far as I am aware is not allowed by Top Eleven or that's what they told me a while ago when I spoke with them regarding tanking.