Left-handed relief pitching was a bit of a problem for the Mariners in 2017, namely, the ineffective performance of Marc Rzepczynski. Enter Kevin Siegrist.
Siegrist is a 28-year-old pitcher who made his debut in 2013. He has had a solid career, posting a respectable 3.99 xFIP with a fantastic 10.48 K/9 rate in his career. He can struggle with his control at some points, as evident by his 4.25 BB/9.
However; 2017 was a disappointment for Siegrist, as he posted an xFIP of 4.58 while walking more than 5 hitters per 9 innings.
Throughout his career, Siegrist has actually faired better against righties than lefties. RHH have a career .192/.276/.349 slash. Siegrist appears to have most of his control problems against the lefties, where his walk rate jumps from 9.5% to 14.%. Used primarily as a LOOGY in St. Louis, Siegrist has a chance at becoming a dominant threat in the middle innings if used properly for the Mariners.
The Seattle Mariners will need to make an impact signing if they truly want to compete in 2018. But as we have already seen with the additions of Ryon Healy and Nick Rumbelow, Jerry Dipoto is always bargain shopping. If he can save enough money on the secondary pieces, he might just have enough left over to buy that shiny new toy.