Barrett, who only recently returned to action following a concussion suffered against Ireland in November, was forced off in the Blues' 32-25 victory over the Highlanders in Dunedin on March 26.
The 30-year-old was taken off in the 41st minute after a collision with Highlanders centre Fetuli Paea.
"I was very relieved to wake up on the Sunday morning after the game feeling clear in my head. I just had a very sore neck," Barrett told Stuff
