Primus, 32, has been injured and out of favour at Fratton Park this term, and Norwich, who made several attempts to sign the player prior to last season, are said to be interested in reviving talks, this time about a loan deal.
The Canaries already have Calum Davenport and Dean Marney in the squad from Tottenham, as well as having taken Charlton's Kevin Lisbie for a month earlier in the season. Injuries to the likes of Jason Shackell have left the defence threadbare, and the flow of goals against has prompted action from the manager.
Plymouth are also said the be in the hunt for the Christian, who would add pace and muscle to the City rearguard and would not break the bank should a permanent move arise.