Casey Janssen and the Washington Nationals have finalized a one-year contract that includes a mutual option for 2016 and guarantees the reliever $5 million US.

Janssen had spent his entire big league career with the Toronto Blue Jays, going 29-24 with 90 saves and a 3.52 earned-run average since 2006.

The right-hander had 25 saves in 30 chances with a 3.94 ERA last year but struggled following a stomach illness during the second half of the season, believed to be caused by food poisoning or a virus.

Washington, which announced the agreement Monday, was in the market for a late-inning arm after trading Tyler Clippard and trading Ross Detwiler to Texas and allowing Rafael Soriano to become a free agent. Drew Storen is expected to be the closer.

Janssen gets a $3.5 million salary this year, and the option is for $7 million with a $1.5 million buyout. He can earn $500,000 annually in performance bonuses based on games: $100,000 each for 40 and each additional five through 60.

Right-hander Eric Fornataro was designated for assignment to clear a roster spot.