Quite frankly, it's 2019 (almost 2020). This is a great tool for associations in terms of providing an easy way to submit registration for a variety of events/sports, but severely lacks in a modern interface.
Once you "become" a part of a team, there needs to be an easier way to communicate. We shouldn't have to log into a site on a web browser on our phone to communicate. My team currently has a separate means of communication because the coach(es) and team manager aren't going to go through all those steps to communicate.
There needs to be a mobile app so that we can quickly access the team messaging and calendar. Think something along the lines of Teamsnap.
I think there's a huge opportunity to fulfill a gap, and drive more user to using the service.