what’s a safe way to get to know him without straight up asking him out

I’ve (24F) recently developed a crush on this guy (28 M) and I want to get to know him better. He and I are definitely well acquainted but I don’t actually know much about him. Problem is, I only see him once a week for pickup soccer. Afterwards some people go to the bar and he’s invited me a couple times (I think he’s just being nice) but I’ve never been. I just don’t really know any of the other guys and only want to talk to him.

I just don’t really know how to approach the situation since this is the first time it’s not a guy I see almost everyday. Plus since we’re playing soccer there’s not much talk time on the field :/ I also don’t have his number and I’m kicking myself bc I had a chance last night to get it and I missed it. Any thoughts?