the only way it works for RTG is if you don't do the HS playoffs part of it. you have to create your player, put him on the team that you want him on, then do RTG using an already existing player, which would be the player you created. also be sure you don't auto-generate names, and have your roster loaded at the time of starting the rtg. a good work-around is to make your player, do the hs playoffs and choose your team, see what your overall/stats are and what your depth chart position is, then exit, create your rtg player according to the stats you earned from your hs career and put him on whatever team you earned a scholarship/walked on to, then start a new rtg using your player. sorry for the long explanation lol.
*disclaimer: this is how it was last year, im assuming it is the same this year. im pretty sure it is, but my bad if its changed.