Runzler signed a minor-league contract with the Rays which includes an invitation to spring training, Marc Topkin of the Tampa Bay Times reports.
Runzler made eight appearances for the Pirates last year, striking out four batters and allowing two home runs over the course of four innings. It was his first major-league action since 2012. He's spent the majority of the past five seasons pitching in Triple-A, where he's had an xFIP north of 4.20 in each season. The veteran left-hander will look to earn a spot in the Rays' bullpen but doesn't look to be a favorite to secure a roster spot.