The Samoan centre has been out since early October, when he pulled his hamstring in the defeat at Racing Metro.
Youngster Tom Stephenson has performed superbly in his absence, but Pisi could be back in the squad this weekend.
“George Pisi is doing well,” said Saints assistant coach Alan Dickens.
“He trained last week so he’s had a full week this week and he’s in the mix.
“Tom has come in and performed well and it’s good in terms of the squad.
“For him to get the 12 or 13 spot, he’s pushing internationals and he’s raising his game, which is a positive thing at the minute.”
Meanwhile, Dickens has confirmed George North suffered concussion in Wales’ recent defeat to New Zealand.
And the wing is a doubt for this weekend’s trip to Italy.
“With the concussion protocol he has to pass each stage so he’s touch and go,” said Dickens.