In Tuivailala, the contending Mariners land a quality middle reliever who figures to become a mainstay in Seattle's bullpen for the next few seasons. He is not dominant but provides solid outings most of the time.

Elledge has the potential to become a much better strikeout artist than Tuivailala out of the bullpen for St. Louis, though for now he remains a prospect. Still, he is a solid addition. This is a good deal for St. Louis.

Tuivalala will provide holds for Seattle but his overall fantasy stock is stagnant as long as his strikeout rate remains below-par. Elledge has more long-term upside as a late-inning reliever but fantasy leaguers need to take a wait-and-see approach for when he actually makes his MLB debut before making a commitment to him.