Starting at 9 am ET, MLS teams will have four hours to begin making new signings or trade players. This represents MLS clubs' first chance to do so since rosters were frozen in mid-September.
While it may be a short window, a lot can happen. For example, last year, the trade of Kei Kamara to the Vancouver Whitecaps and Walker Zimmerman's move to LAFC were both completed during the four-hour stretch.
Once the window closes, no roster adjustments may occur until FC Cincinnati makes its selections in the MLS Expansion Draft on Tuesday. Following that, Free Agency begins later on Tuesday, with the MLS Waiver Drafts and the MLS Re-entry drafts to follow later in December.