What does it mean to 'play rookie'?

To "play rookie" means to behave in a manner that is naïve or inexperienced, often by making decisions or taking actions that reveal a lack of knowledge or understanding about a particular situation. It can also imply adopting a humble or unassuming attitude, as if one is new to a field or task, even if they may have some experience. The phrase can be used both seriously, to acknowledge inexperience, or humorously, to poke fun at someone’s blunders.