WALTHAM, Mass. -- Quick hits after the Celtics practiced Wednesday at HealthPoint:

* Green remains out of action: Celtics swingman Jeff Green, officially signed Saturday to a one-year, $9 million deal, remains sidelined and Celtics coach Doc Rivers called it a "big concern." Hop HERE for more.

* Pierce, Rondo out for a couple of days: Boston went through much of Wednesday's practice without captain Paul Pierce (sore right heel) and Rajon Rondo (sprained right ankle). "Paul went [Tuesday], then his foot got sore, so we just decided that we’ll shut him down for a couple of days," Rivers said. "[Team trainer] Eddie [Lacerte] thinks about two days. Rondo did some stuff today, but we didn’t want him running because, with a sprained ankle, it’s too early to push that. Eddie thinks it’s about a couple days with him too."

* Cramming a two-a-day into one session: Rather than having a long break between sessions, the Celtics elected to essentially cram a double session into one four-hour practice block with a 45-minute break in the middle. Rivers sounded uncertain if he'd do that again. "We tried something today, I don’t even know if I like it, to be honest. You just try new things. We went for about two hours, took a break for about 45 minutes, stretched them and watched film, then we came back out and finished the scrimmage instead of breaking up, going back home, and then come back and doing a two-a-day. I'm not sure if I actually liked it. I’ll get the input from the coaches and the players, but we’ll find that out."

* KG & JO the practice stars: Rivers raved about both Kevin Garnett and Jermaine O'Neal after Wednesday's session. Those concerned about whether O'Neal is fit to handle the rigors of a full season can rest a little easier (for now anyway) with a positive initial report from Rivers. "The other guy that’s been phenomenal has been J.O. He looks great," Rivers said. "It’s amazing the difference watching him at this time last year in camp, just the fact that he knows stuff, and he’s comfortable."

* Loose balls: Rookie JaJuan Johnson drew a big media crowd Wednesday. The first-round pick chatted about his experiences on and off the court since the lockout was lifted. Asked if Garnett knows his name yet, Johnson relayed how he's been dubbed "New" or "Rook" by the nickname-preferring Garnett ... The team plans to practice Thursday afternoon at TD Garden, then will hold a scrimmage there Friday night (open to corporate sponsors and season-ticket holders only) ... It will be the rookies' first time visiting the Garden and seeing the team locker room.