Salam, sometimes when my friends play sports they call each other by the name of famous athletes. For example, someone might say "he is LeBron." A lot famous athletes are non-muslim. My friends intend to make an analogy to their style of play, but could this be considered takfir since they are calling each other by the names of people who are kafir?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Simply calling a Muslim by the name of a non-Muslim player is not considered as considering that Muslim as a non-Muslim.
As for the ruling on that, then if it is for mocking him and belittling him, then it is undoubtedly forbidden.
But if it is not for mocking him and belittling him, and it was said as a form of praising him by comparing him to that player due to his excellence in the way he plays, for example, or the like, then it does not appear that it is prohibited.
We advise you to avoid whispers, ignore them, and not be preoccupied by them.
Allah Knows best.
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