The South African-born midfield star has been drafted into the Sharks' Super 14 squad after seeing his English season come to a premature end with Sarries failing to reach the Guinness Premiership play-offs and falling to Northampton Saints in the semi-finals of the European Challenge Cup.
Barritt played 50 games for the Sharks before moving to England and has been re-recruited following untimely injuries to Springbok duo Francois Steyn and Adrian Jacobs.
Steyn is ruled out of the rest of the Super 14 tournament with a knee injury, while Jacobs is currently struggling with a shoulder problem. Those injuries came on top of a knee injury that forced another Test centre, Walon Murray, out of the competition before it even started.
"Brad's return to us could not be better timed given our injury problems. He will add a lot of experience and he will slot right in because he was gone just six months," said Sharks assistant coach Grant Bashford.
"He's been playing week-in and week-out, so there are no fitness issues and, from what we have seen on TV, he is in fine form."
The Sharks are bidding for a play-off place in the Super 14 and face the Waratahs this weekend. If Barritt slots in well enough at his old club then his loan period could extend an extra month to encompass the Sharks' clash with the Lions in Durban.