After being medically cleared to participate in all practice activities two weeks ago, Boston Celtics guard Rajon Rondo says he feels confident in his surgically repaired knee.  Rondo admitted on Friday he could be ready to return by the end of January, MassLive.com reports.

Per Jay King of MassLive:

"Rondo: 'I have confidence in my knee.'  Then said it might be mid-to-late January, maybe later."

Rondo, who tore his ACL in January, has been reticent to put a timetable on his return.  Dr. James Andrews cleared Rondo for full-contact on Dec. 13, and the All-Star wasted no time getting back into scrimmages.

He organized a scrimmage after practice on Friday and looked good in the 5-on-5, which lasted between 30 and 45 minutes.

"(I) know a lot goes into returning to game action from ACL but must say Rajon Rondo looks aggressive, explosive, dominant in (Celtics) scrimmage," Scott Souza of the MetroWest Daily tweeted on Friday.

Celtics teammates Jared Sullinger and Gerald Wallace were among those who stayed after practice to scrimmage against Rondo, according to MassLive.

"The main reason why I stepped out there was to help build (Rondo's) confidence for when he's back on the court," Sullinger told MassLive.

Wallace added: "This is basically us trying to get (Rondo's) wind and his rhythm back on the court."

First-year coach Brad Stevens acknowledged two weeks ago that Rondo was unlikely to return before January.

"He won't play in games, is what I've been told, until after the first of the year," Stevens told ESPN earlier in the month.  "And that still is, we're talking in big generalities there.  I don't know when that means.  It could mean a month from now, it could mean six weeks from now.

"There's a lot of different variables that have to be met for him to be cleared for games."