Suggestions on Fallback Liquid Personalization Code to remove a comma?

Hi there, I love the Liquid personalization. I need a recommendation though. 

As an option I like to place the subscribers first name at the top of the email following by a comma, like this: "Jeff," 

Question: For a fallback option for subscriber with no first name, how do I not only strip the name, but the comma as well?

I already use the fallback option: Hi {{ subscriber.first_name | strip | default: "there" }},

But, if possible, would like to have this other option as well.

Thanks for any suggestions!

Matt