It's possible you might be thinking of a different episode or character. It's also possible that you might be mixing this episode with another scene where a character's face is bruised, but not necessarily Q's.
Could you provide more details about the episode you are thinking of? For example:
* What season and episode is it?
* What other events happen in the episode?
* Who else is involved in the scene?
With more information, I can help you pinpoint the scene and why the character's face might have been bruised.