The 32-year-old has been without a club since leaving Blackburn Rovers at the end of last season.
Before joining Blackburn, he was an almost constant presence in the Middlesbrough backline for over six years.
He also counts Hull City among his former clubs, having spent time on loan with the Tigers during his Liverpool days.
According to Bristol Live, he is currently training with Bristol Rovers as Gas boss Joey Barton weighs up whether or not to offer a deal to the defender.
Barton’s squad is currently light on defenders, with injuries having struck in the early stages of the season.
Ayala would bring a considerable amount of experience to Barton’s squad, although will most likely be lacking match fitness after months spent as a free agent.
