Pittsburgh opted not to re-sign Roberts to a new contract following the season and traded both he and Ryan Malone – who was also a pending free agent – to the Tampa Bay Lightning in exchange for a third round draft pick on June 28, 2008. The deal gave Tampa Bay a brief window in which they had exclusive rights to negotiate a contract. He agreed to a one-year contract with the Lightning. Another injury, to his elbow, caused Roberts to miss 33 games of the 2008–09 season. He played only 30 games and recorded seven points. The Lightning placed him on waivers as the 2009 trade deadline approached, but no team claimed him. Nine days after playing his final NHL game, an 8–6 win in Calgary where he recorded an assist, Roberts announced his retirement on March 10, 2009.