shower diverter stem leaking - no biggie or repair needed?

Hello,
I wondered how much of an issue this really is. When pushing the shower diverter stem in to engage shower, I noted a drip or small trail of water running out. Is this something that could allow water to enter areas behind the shower or it is something that does not need repair right away?

It is a sealed tube so the leak is all outside the wall, but since the repair amounts to removing the plate, unscrewing the diverter, and screwing a new one in, why wait with the repair. When it reaches the age where it leaks, one of two things usually happen.
1. It starts sticking so you have to pull it out after showering, or
2. It breaks and that pin "shoots" out, often striking a delicate part of your body.

I'd love to see one shoot out!

Are there o-rings on the pin or something? Just trying to visualize the water path (I have searched on-line and can't find a diagram). Thanks for your response.