The Padres also agreed Wednesday to a minor league deal with catcher Gregg Zaun that includes an invite to spring training.
Qualls split last season between the Arizona Diamondbacks and Tampa Bay Rays, going 3-4 with a 7.32 ERA in 70 appearances. He converted 12 saves in 16 opportunities for the Diamondbacks before being traded to the Rays on July 31.
The right-hander joins an outstanding bullpen that helped keep the Padres in playoff contention until the final day of the regular season. He gets a $1.5 million salary this year and the deal includes a $6 million club option for 2012 with a $1.05 million buyout.
Zaun spent 2010 with the Milwaukee Brewers, hitting .265 with two home runs and 14 RBIs in 28 games.