Gay, an undrafted free agent in 2013, provides competition at punter against Brian Moorman and also provides an option as a kickoff specialist.
This preseason, Gay punted four times for an average of 35.2 yards and handled kickoffs for the Panthers.
The Bills waived punter Jake Dombrowski and kicker Dustin Hopkins on Monday, but coach Doug Marrone said he is still considering keeping a kickoff specialist on the roster.
"We’re trying to make sure that we have a guy as a kickoff guy," he said. "That hasn’t changed."