Naholo has a new fracture to the same leg he injured before last year's World Cup. The injury happened late in Friday night's game against the Blues and was confirmed after an X-ray on Monday.
Team doctor Greg Macleod was looking at the positives and said the star winger is expected to miss six to eight weeks.
"While this is very unfortunate for Waisake, the positive news is that this injury is not as bad as his last fracture," Macleod said in a press release.
"He is already managing well and it's expected his rehab will take six to eight weeks."
Tanaka, the Japanese international halfback, picked up a calf injury during the last training in Auckland and is expected to miss four weeks.
"Fumi [Tanaka] has torn his calf and we expect the recovery to take four weeks," Macleod said.
Tanaka, who is generally used as a back-up to Aaron Smith, was replaced by Otago halfback Josh Renton in the reserves on Friday.
Head coach Jamie Jospeh was philosophical about the injuries, saying that you have to expect, and deal with, them.
"To lose players for an extended period is always disappointing, but you have to expect injuries to occur at some point," Joseph said in a press release.
"As a group we simply deal with it and move on. The focus for the players now will be to rehab well and work to make themselves available again."
Naholo will not return to Fiji for treatment, as he did last year in order to recover to play for the All Blacks at the World Cup. Instead his rehab will be guided by Macleod.
