New players only come through the draft which occured at the start of the season. Each season you draft 3 players.
Your 3 drafted players are Sampaio
(3073779), Nóbrega
(3073760), and Silva
(3073764)Though you only get 3 new players per season, rather than 16 like in HT, the new players in BB are actually pretty good. Of my 6 draft picks over 2 seasons, 2 are starters for my team (or would be except they're both PG), another is a backup, two were sold on the TL, and only one was fired.
Unless you are doing team training in FT or stamina, you probably have too many players on your roster. You're paying salaries, but not getting any training or playing from them. I suspect that some of your draft picks would be more productive than some of your older players. They're probably already as good, and have much more future potential.