Hibbert suffered a dislocated knee in 2010 that forced his retirement earlier this year, but the 27-year-old has recovered sufficiently enough to try his luck with the Conference Premier side.
Chief executive Ian Neale told BBC Sport: "Dave signed on non-contract terms as we don't know if it'll work out.
"He has been with us for a few weeks but it is one thing training. The real test comes in a game when you have to stretch for the ball or go in for a full-blooded tackle."
Hibbert is unable to play in the Football League due to the terms of his insurance settlement.