Seattle Mariners reliever Erik Swanson has been untouchable

A lot of the focus has been on Kendall Graveman out of the Seattle Mariners bullpen, but there is another guy that has completely transformed himself into a really good reliever. That guy is 27-year-old Erik Swanson. The 6’3″ right-handed pitcher came to Seattle along with Justus Sheffield and Dom Thompson-Williams in exchange for James Paxton.

Swanson was a small part of the deal and he honestly hasn’t been very impressive up until now. The Seattle Mariners reliever made a huge leap between 2019 and 2020 but with nothing to show for it. Finally, his improvements are turning out great although it’s a small sample size.

The Seattle Mariners magically increased Erik Swanson’s velocity

In 2019, Swanson threw 58 innings and recorded a 5.74 ERA. That season, his average fastball velocity was 92.7mph. He also threw a slider and changeup along with his four seamer.

In 2020, Erik Swanson made a huge leap in velocity where his fastball was 95.6mph on average. He also scratched his changeup and went with a split finger. Although he made some big adjustments between 2019 and 2020, he didn’t get much of an opportunity to use it. He threw just 7.2 innings and recorded a 12.91 ERA, which isn’t a great sample size at all.

Now in 2021, Erik Swanson’s numbers are looking elite, but he has a small sample size again. It might be a little too early to tell whether Swanson has finally turned a corner but he has allowed only one run in 11.2 innings. This is significantly better than his past two years.

If you look at his advanced metrics, Erik Swanson isn’t that far off from Kendall Graveman.

• Erik Swanson
  • .113 xBA
  • .269 xSLG
  • .178 wOBA
  • .225 xwOBA
  • 29.3% K%
  • 1.98 xERA
• Kendall Graveman
  • .219 xBA
  • .292 xSLG
  • .146 wOBA
  • .255 xwOBA
  • 29.3% K%
  • 2.54 xERA

I will reiterate again, Erik Swanson has only thrown 169 pitches this season compared to Kendall Graveman’s 236. That being said, it’s still a bit too early to put Erik Swanson in the “elite” category but if he keeps this up for a few more weeks, it’s not a crazy statement.

The Seattle Mariners bullpen has been dealing with a lot of injuries and inconsistent performances from some of our reliable guys, so having Erik Swanson break out like this is huge. Also, with teams starting to pull away from the middle of the pack, you start to wonder whether Erik Swanson will be trade bait or remain with the Seattle Mariners this season.