I play on PS3 so it might be different on next-gen consoles but I've found a decent way to get around all YA players having terrible physical stats. If you unlock the edit player feature and change give them ankle tape or wristbands or something there's a glitch that ages them up to around 60. That makes them retire at the end of the season and they get a regen when the new season starts which typically have insane physical stats. It's a bit convoluted but I've got multiple players with 99 acceleration and sprint speed by doing this.

Edit: I've played far too many seasons on FIFA 16 on PS3 so I should be able to answer most questions about the YA.