The 2021 trade deadline was the first of two deadlines where we saw the Nationals act as active sellers, as they shipped away a number of fan favorites in an effort to replenish what was a depleted farm system. One of those trades would include Mike Rizzo sending reliever Daniel Hudson to the San Diego Padres, netting a return of fellow reliever Mason Thompson and infielder Jordy Barley.
At the time, most Nats fans didn't think much of this trade. Mason Thompson made his MLB debut in 2021 for the Padres, surrendering one run across three innings of work, leaving Nats fans with little volume to base their expectations off. In the 27 games he would pitch in for the Nats that year, he threw to the tune of a 4.15 ERA and 1.938 WHIP. In 2022, those numbers improved to 2.92 and 1.135, respectively. Now, it's 2023 and he's off to a blazing hot start. Thompson leads the major leagues in innings pitched by a reliever with 18.2, and is tied for third in fWAR, already racking up 0.5.
So, what makes Thompson so good?
For starters, his pitch selection works seamlessly together. His sinker has only improved over his career and has already accumulated a run value of -2 this season. Opponents are hitting .216 off his sinker, with a slugging percentage of .351. Combine that with his wipeout slider that already has a run value of -3, hitters are finding out the hard way how good Thompson is. Opponents are hitting a measly .118 against his slider, with a .118 slugging percentage, meaning every hit that has been off his slider has been a single. Those two pitches combine for 90.3% of Thompson's pitches so far this year, and based off those numbers, that most certainly isn't a bad thing. Mason will still mix in a 4-seamer and a curveball, two pitches he throws 6.0% and 3.7% of the time, respectively. Despite the low usage, his 4-seamer already has -1 run value this year, and opponents are hitting a solid .000 off both of those pitches.
Mason Thompson has been nothing short of elite this year, cementing himself as honestly one of the better relievers in the game. Yet Davey Martinez and his staff continue to use him in a long relief kind of role. Just this Tuesday evening, he threw three shutout innings in relief of Josiah Gray to secure the win and earn himself a save. The fact he was able to throw three effective, shutout innings is impressive nevertheless, but it's not the role fit for a guy like Mason Thompson. A guy with his stuff and potential should be at the back end of the 'pen, rather than the front.
Ultimately, it's not up to me or anyone else besides Mike Rizzo and Davey Martinez, but hopefully they see what many Nats fans do and give him the closer role to see if he truly has what it takes to be an elite closer. If he's able to keep up what he's been showing us thus far, the Nationals may have found themselves a gem in Mason Thompson. A result of a somewhat random trade deadline deal, Thompson alone proves the value of flipping guys at the deadline for anyone you can add to your farm system, something the Nats are aiming to do this season.