WALTHAM, Mass. -- The Boston Celtics worked quickly to fill their roster Friday before their first day of training camp, but a logjam of paperwork at the league office left them with only nine players on the court for the first session of the season.

The team officially inked three free agents in forward Chris Wilcox, swingman Marquis Daniels, and forward/center Greg Stiemsma. They were able to join the six players under contract -- Kevin Garnett, Ray Allen, Paul Pierce, Rajon Rondo, Jermaine O'Neal, and Avery Bradley -- for an evening practice (Celtics coach Doc Rivers joking that assistant Tyronn Lue participated in order to bring the team to 10 bodies).

Rivers later revealed that restricted free agent forward Jeff Green was in attendance, but could not participate, after agreeing to a one-year deal -- presumably at the $5.9 million qualifying offer the team extended before the lockout. Green was one of a handful of players that didn't clear the necessary hurdles, even after the Celtics waited an extra 75 minutes to start practice.

Also in attendance were both the team's rookies in first-round pick JaJuan Johnson and second-round selection E'Twaun Moore, both of whom inked their first-year pacts. Undrafted rookie free agent Gilbert Brown, free agent big men Michael Sweetney and Jamal Sampson were also expected, but not spotted for the session.

Later in the evening, Boston officially completed a swap that landed Keyon Dooling and a protected second-round pick from the Milwaukee Bucks in exchange for the draft rights to Albert Miralles (the team used a trade exception from dealing away Daniels at the deadline last year to facilitate the salary addition).

Rivers said he expects to have all those other bodies available as early as Saturday and the team will soon add veteran big man Brandon Bass after the sign-and-trade swap that sent Glen Davis to Orlando on Friday.

In all, Boston could have as many as 17 bodies available this weekend and Rivers said there were still moves to be made as the Celtics look to fill out their bench (with eyes on adding experience at the center position).