The veteran prop's been struggling with a muscle tear in his right shoulder but has survived what appeared to be a busy training session in Christchurch on Tuesday.
Franks has to get through the full week to be considered for Saturday night's final round robin game against the Rebels.
"It was great for him to get a good session in today," said assistant coach Ronan O'Gara. "He's tracking along nicely.
"He's been out for a substantial amount of time, so you have to be careful. He's such a prized asset that you've got to make sure you get his return to play right."