Gaither was transported to Massachusetts General Hospital, where X-rays on his neck and shoulder came up negative, team sources told NFL Network's Jason La Canfora. An MRI still needs to be done and will be taken at another location.
"We knew it wasn't serious (even before the tests)", Ravens coach John Harbaugh said. "We'll see how long he'll be out."
Gaither was dropping back as he blocked Patriots defensive end Jarvis Green. Meanwhile, New England defensive end Ty Warren rushed Joe Flacco from the other side and shoved him into Gaither's back after the Baltimore quarterback released a short incomplete pass.
Flacco and Gaither both went down, but Flacco quickly got up.
Gaither remained on his back for about 10 minutes, surrounded by medical personnel. He was strapped to a board, which was lifted onto a cart that took him off the field.
The Ravens drafted Gaither in the fifth round in 2007 while he had two years of eligibility remaining at Maryland. He played six games as a rookie, starting two of them. He played in all 16 regular-season games last year and started 15, then started in the Ravens' three postseason games.
Gaither started in all four games this season.
The Associated Press contributed to this report.