farm league

Short definition from Wiktionary

Noun

1. 1
   One or more minor league teams owned by a baseball franchise and used as a training and testing ground for rookies, who, if they perform well, move on to play in the main major league team.
2. 2
   A minor league team from which scouts recruit players for the major league.
3. 3
   A position or venue from which talent is recruited for showing potential.