Assertion: league | /r/Synonym | usl pro
Facets:
value: in 2013
type: TEMPORAL
Source sentences:
text: MLS began integrating its Reserve League with the league then known as USL Pro in 2013, and after the 2014 season folded the Reserve League, with MLS now requiring all teams to either affiliate with a USL team or field their own reserve side in that league.