The coach is standing alone, the deep contrast supports the idea, but with the team... I agree the photo is marginal to the idea of being solo. However, the picture does have a lot of merit as a part of a season record of the team & coach. I like it.
I take it the coach is your Solo on this picture. Or maybe the whole team as one but I don't really find it properly portraits the criteria. And the photo doesn't do a whole lot for me. Sorry.