Blake Griffin is on target to return from his routine arthroscopic procedure to remove loose bodies from his right knee on Dec. 20.

Griffin missed his 13th straight game on Wednesday night.

Rivers wouldn't specify a return date, but team sources said the Clippers are hopeful he could return during the last week of January, which would correspond with the initial diagnosis of four to six weeks.

"I don't know if he's ahead of schedule, on schedule, but all things are go for him -- and that's very positive for us," Rivers said.