And in between those two? That's the MLS Waiver Draft.
What is that exactly? Here's what you need to know:
How does it work?
The Waiver Draft consists of players who have been waived by their clubs but don’t meet the minimum years of service requirement for the Re-Entry Draft or Free Agency — so mostly young players who are relatively new to MLS.
Under-contract players who are selected in the Waiver Draft will be automatically added to the drafting club’s roster. Clubs that claim out-of-contract players must issue a genuine offer to the selected player.
When is it?
It’s on Thursday, Dec. 15 at 2 pm ET. A list of players eligible for the waiver draft are officially released a day earlier.
What’s the order of the draft?
The order is determined by the reverse order of the final standings in the MLS season, taking into account postseason performance. The Chicago Fire get the first pick and the MLS Cup champs get the 20th pick.
Expansion clubs Atlanta United FC and Minnesota United FC will pick 21st and 22nd, respectively.
Will there be much activity?
Probably not. Last year, the Colorado Rapids were the only team to make a move when they selected midfielder Michael Azira from Seattle Sounders FC. And in past years, it's usually only two or three players that get picked in a given draft.
But Azira turned out to be a key contributor for the Rapids, starting 28 games. And he relished the chance to face the club that let him go in this year's MLS Western Conference Championship.
Are there other success stories?
The Rapids have made a habit of plucking steals. A year before they picked Azira, they snatched up Bobby Burling, who started 38 games over the last two seasons for them.
Generally speaking, though, MLS teams aren’t likely to find starters in the Waiver Draft and most usually don’t take anyone.
What happens to players not taken?
Of the 29 players eligible and not taken in last year’s Waiver Draft, several found new homes in lower-division American leagues, while others departed for different countries.