Cuthbert has been out of action since suffering a tore hamstring in Wales' RBS 6 Nations title triumph over England, in which he scored two tries in March.
He was scheduled to make his comeback in Cardiff Blues' final RaboDirect PRO12 clash of the season, against Ulster on Friday night but pulled out before kick-off.
"It was just a pre-caution," said Cuthbert.
"Phil Davies decided I should not risk it and it was probably a sensible idea because there was nothing much on the game.
"The rehabilitation has been going well but it is important I don't rush things with such an important couple of months going up."
Warren Gatland was given a further worry when North was forced off with a rib injury as the Scarlets were humiliated by Benetton Treviso last Friday.
The giant wing reported some breathing difficulties but Scarlets head coach insists North has no long-lasting complaints and will be available this weekend.
"George has trained this week. He took a heavy bang to the sternum but he's been good." said Easterby.
"There are a few sore bodies and we will probably wait until Thursday before naming our team."