I used to play for soccer team and a transwoman used to train and play with us sometimes. We didn't know she was trans at the time (only after she detransitioned later) but she was very obviously much stronger, faster and more aggressive than all the other players. Women on the team did not like playing against her as they were likely to be injured during tackles. I play mixed soccer as well, so am very aware of the differences playing against men vs other women. As this becomes more widespread it will only put women off playing mixed sports. This player wasn't especially talented compared to a standard male player - if they had been that would only have made the situation much more demoralising for the female players. This isn't at any kind of professional level - just normal, entry level grassroots sports.