Yeah this is one way to add conflict! Usually things like rivals, an oppressive group/faction or a deadline are great ways to add conflict in anything.
Like everyone says it’s short but I’m glad you’re making a sports themed game since I don’t see many of those. Plus I’m a huge time sports fan so that helps too. Good luck with it. I can’t wait for what you come with it.
It’s very barebones so far and there isn’t much feedback I can add. Just try to develope overall concept more. In sport fiction the most important thing in my opinion are engaging and interesting characters, especially in written fiction since you can’t just overcompensate with stunning visual and fight choreography (although it is important). So I would focus on that. Fleshing out main character would also greatly increases immersion. As an amateur boxer myself I will try to give some feedback on technicalities when it comes to actual matches but before that focus on developing and expanding that boxing world you creating.