SAN DIEGO -- With an intriguing but young group of starting pitchers, the Padres have spent the offseason trying to build a lockdown bullpen to shorten games and ease the burden on their rotation.

That bullpen continued to come into focus on Monday.

San Diego signed 28-year-old right-hander Pierce Johnson of the Hanshin Tigers to a two-year deal with a team option for 2022, the club announced. The deal is worth $5 million over those two years, ESPN's Jeff Passan reported.

In 58 appearances for Hanshin last season, Johnson posted a 1.38 ERA, and his peripheral numbers were just as impressive. He fanned 91 hitters in 58 2/3 innings, while surrendering just two homers and 5.2 hits per nine innings.

Still, the signing is a bit of a risk, given Johnson's big league track record. With the Giants in 2018, Johnson posted a 5.56 ERA, while striking out only 36 hitters in 43 2/3 innings. A first-round Draft pick of the Cubs in 2012, he also pitched one scoreless inning for Chicago in '17.

Johnson won't be expected to fill a high-leverage role, at least at the start. Kirby Yates will anchor the 'pen as the closer, with newly signed lefty Drew Pomeranz and flame-throwing righty Andres Munoz serving as the primary setup men.

Lefties Matt Strahm and José Castillo will also pitch late in games. And if everything goes according to plan, Johnson might serve as a right-handed complement to those two.

Johnson's arrival seemingly leaves two places available in the Padres' bullpen. Among the pitchers competing for those two spots are right-handers Luis Perdomo, Javy Guerra, Trey Wingenter, David Bednar and Gerardo Reyes. Prospects Michel Baez and Adrian Morejon, meanwhile, will be given a chance to start again this season, but they could potentially fall into the bullpen mix as well.

The list of options doesn't end there. Within the past week, San Diego has also added right-handers Kyle Barraclough, Chih-Wei Hu and Jimmy Yacabonis on a trio of Minors deals.

The Padres entered the offseason with some serious upside at the back end of their bullpen. They've spent the past two months reinforcing it.