"Panasonic just want him to have some medicals today and that's fine, that's par for the course, and he's gone and done that," Hansen said.
"[Team doctor] Deb [Robinson] has taken him to get some tests and once we finalise all that we will get the red light or the green light.
"He's sore, but all those Chiefs' boys are sore ... he's had a big season, he's played about 20 games and played pretty well so it's not surprising."
If Williams was ruled out it would be a blow to Hansen who had personally asked the player to extend his stay and said as recently as Sunday that only paperwork needed completing for him to be available. Ma'a Nonu would play at second-five, with Tamati Ellison or Ben Smith considered for centre, if Williams was ruled out.
"If Sonny doesn't play we've got another fella that's pretty big at 12, a similar type of player, so we're very lucky and blessed in that way."
Hansen's appraisal of Read's progress makes for better news, however. Read, who was to play in the extended training run against the Counties and Auckland ITM Cup teams in Pukekohe last night, was recovering well from his rib injury.
"He's come through training well and he's done quite a bit from a physical point of view over the last 10 days," Hansen said. "He's one of the best No 8s in the world. He understands the game and he's a great reader of the game so he's an important part [of the team]."
Crusaders' lock Luke Romano, who has been carrying a shoulder injury, will also be considered for the Wallabies match next Saturday. None of the Chiefs players was available for the run-out at Pukekohe following their Super Rugby triumph over the Sharks last weekend.
APNZ