Team executive vice president Andrew Friedman said Tuesday a deal with the free-agent left-hander was "pretty official," although some details had not been finalized.
"He brings a lot to our bullpen," Friedman said of Shouse, who was 5-1 with a 2.81 ERA in 69 appearances with the Milwaukee Brewers in 2008.
"He's had a tremendous amount of success the last two seasons, especially against left-handers. He generates lots of groundballs. He doesn't walk guys. He keeps the ball in the park," Friedman said. "We feel like he's going to help diversify our bullpen even more and strengthen it beyond where we were earlier this offseason."
In nine major league seasons, Shouse is 12-9 with a 3.65 ERA in 422 games for Pittsburgh, Boston, Kansas City, Texas and Milwaukee.