He might be afraid to look bad that he needs so much help. Does your workplace have a culture where helping each other is normal, or maybe even cherished? Or does he have to fear negative consequences for asking for help?
Does it make look you bad when you help a lot and it isn't explicitly mentioned? Or is it normal to help each other and it's expected to you spend a sizeable amount of your time helping others?
You said you think it might make you look pathetic. I would question that assumption in the context of your workplace.
Also, a standup is a place to communicate on what you need to do and what you need to do it. It is not a place for progressreports, so I consider it normal not to go into detail on who helped whom.
Once you figured out how things are regarded in your workplace, I would talk to the coworker first. A simple: Hey, I kinda help you a lot, and I am a bit worried that my manager doesn't realize how much time I spent on you. I would appreciate if you mentioned it, so he knows what up. I'll comment on the good progress you make, that way we both look good!
Demanding credit often looks pathetic. Politely asking for it is often more effective.