3 under the radar bullpen arms the Mariners should look at in free agency

The Paul Sewald trade left a void in the back end of the Mariners bullpen. While the bullpen as a whole was great in 2023, relief pitching can be volatile from year to year. Could these under the radar type pitchers help the Mariners in 2024?
Boston Red Sox v Baltimore Orioles
Boston Red Sox v Baltimore Orioles / G Fiume/GettyImages

The Mariners will surely add to their bullpen for 2024. No, I do not expect the M's to go out and spend $100,000,000+ on Josh Hader, but there are plenty of names that you may not have heard of that could help. Keep in mind, Justin Topa, Gabe Speier, and Tayler Saucedo were all guys who the Mariners got for next to nothing. Jerry Dipoto, if nothing else, can spot pitching talent that some teams just can not see.

For the most part, the pitchers I am going to talk about here will not sign a huge, multi-year deal. The AAV could be on the higher side, but for the most part, these kinds of moves are on the "Low risk, high reward" kind of scale. These are pitchers who may not have proved they are ready for Major League competition, or maybe they are on the backside of their career.

Shintaro Fujinami, RHP

Before you click off of this article, just hear me out. I know his 2023 was bad. Like, real bad. I get it. Shintaro signed with the Oakland Athletics during the last offseason from Japan. Even in Japan, he struggled with walks. His career walks per 9 innings in Japan was 4.1. That translated to the US with a 5.1 BB/9 innings last season. He was traded before the trade deadline to the Baltimore Orioles, where he performed much better. His stats for each team are as follows:



















Now for the good side. His average fastball velocity sits at 98.4 MPH. According to Baseball Savant, he ranks in the 97th percentile in velocity. If he could limit the walks, his chase rate (23%, 4th percentile) would come up substantially. That will help his overall numbers, and I am not a firm believer that the Mariners pitching lab can fix whatever is broken with Fujinami. I think he has a lot left in his tank, and signing him brings little risk. He will not command a multi-year deal, so I think he is well worth the risk.

Drew VerHagen, RHP

Drew VerHagen spent his 2023 season with the St. Louis Cardinals. He had little success in his career until last season. He spent 2014-2019 with the Detroit Tigers, pitching to a 5.11 ERA WITH A 1.43 WHIP. He did not pitch in the Majors again until 2022 when he really struggled with the Cardinals. He came into 2023 with little expectations, and he really performed well.

VerHagen throws a 5 pitch mix. In 2023, he threw his sweeper almost 32% of the time, with opposing batters hitting just .128 against that pitch. He also throws a 4-seam fastball, sinker, cutter and a changeup. His cutter was his worst pitch by far in 2023. Opponents hit .478 against his cutter, which he threw 12.6% of the time.

In 61 innings with the Cardinals, he pitched to a 3.98 ERA, striking out 60 and walking 26. His Baseball Savant numbers do not jump off the chart, but turned himself into a solid pitcher last season. Even in the Mariners pitching lab, VerHagen will not turn into Matt Brash or Andres Munoz. But I really do think he can be a solid, low-leverage arm who could help at the back of the pen.

David Robertson, RHP

David Robertson is the biggest name on this list, and the most accomplished name as well. Robertson spent much of last year as the Closer for the New York Mets, before being traded at the trade deadline to the Miami Marlins. He finished the season with a 3.03 ERA in 65.1 innings. He struck out 10.7 batters per 9 innings and only walked 3.1 per 9 innings. He saved 18 games between the Mets and the Marlins, though most of them came in New York (14).

Robertson struggled a bit down in Miami. He pitched to a 5.06 ERA and walked 12 in his 21.1 innings for the Marlins. the Mets signed him to be the bridge to star closer Edwin Diaz, but Diaz ended up with a torn Achilles during the World Baseball Classic and missed all of the 2023 season. He was masterful for the Mets, pitching to a 2.05 ERA in 40 innings. David will turn 39 in April, so should the Mariners take a chance on him, it will be a short-term deal. The AAV could be on the higher end, but Robertson showed that he can handle high-leverage innings, and that is just what the Mariners need. As always, go Mariners!