Brian, it makes sense to me that while his ankle was immobilized that he looked for the necessary mobility during basketball in his hip, leading to this new pain. The hamstring tightness probably only contributed in the sense that its tightness caused the mobility to be found in another area of the hip. The question is what to do about it, and I don't know for sure. Here are some links to info on groin and adductor pain in athletes. See if they might be helpful or at least lead you to a clearer search for what you need to do.
http://www.sportsinjurybulletin.com/...-injuries.html
http://www.sportsinjurybulletin.com/...treatment.html
Sports Injury Bulletin is a cool site. If those are not exactly on track, then you might be able to search that site and find what you need.