Eddie Johnson and Tim Cahill are among four MLS designated players left unprotected by their clubs ahead of the league's expansion draft.
The 18 existing MLS clubs revealed a list of 240 players from which Orlando City SC and New York City FC can choose to fill out their teams on Wednesday.
The new MLS clubs will have 10 picks each but can only take up to two players from a single team.
D.C. United failed to protect Johnson following a year in which the striker at times struggled to produce and also had to apologize to his teammates in May and to fans in August after some controversial comments.
Cahill has a year left on his contract with the New York Red Bulls but has also hinted that he might like to return home to Australia.
Sporting Kansas City forward Claudio Bieler and Philadelphia goalkeeper Rais M'bolhi were the other designated players left unprotected.
Many other MLS veterans will also be available to be selected, including forwards Kenny Cooper, Conor Casey, Jairo Arrieta, Dominic Oduro, Alan Gordon and Peguy Luyindula, midfielders Mauro Rosales and Davy Arnaud, defenders A.J. Soares, Marvell Wynne, Corey Ashe and Jackson, as well as goalkeepers Donovan Ricketts, Troy Perkins and Jon Busch.
For a full list of unprotected players, click here.