The Wizards will hold their fourth training camp practice Friday.
The entire Wizards roster was warming up 90 minutes before practice, something John Wall said never happened before.
The session will satisfy the NBA's mandate requiring all teams to hold at least one open practice
Blue appeared in three games for the Celtics last season
Orton played on the Wizards' summer league team
Butler will have the chance to compete for the final spot on the Wizards roster.
The Wizards wrapped up training camp at George Mason with a practice that included the return of Trevor Ariza and some music by rapper Drake.
Otto Porter Jr. and Trevor Booker didn't practice again, but Trevor Ariza also sat out the fourth day of training camp with a sore right calf.
The third overall pick misses out on the first day of training camp, is day to day.
Former George Washington star Pops Mensah-Bonsu is among four free agents expected to attend Wizards training camp.