Can erratic reliever Thompson find consistency at last?

PLAYER REVIEW: MASON THOMPSON

Age on Opening Day 2024: 26

How acquired: Traded with Jordy Barley from Padres for Daniel Hudson, July 2021

MLB service time: 2 years, 42 days

2023 salary: $724,400

Contract status: Under club control, arbitration-eligible in 2025, free agent in 2028

2023 stats: 4-4, 5.50 ERA, 51 G, 1 SV, 54 IP, 62 H, 35 R, 33 ER, 4 HR, 22 BB, 44 SO, 4 HBP, 1.556 WHIP, 79 ERA+, 4.03 FIP, -0.4 bWAR, 0.5 fWAR

Quotable: “Mason is still a big part of our future. He’s had such a weird year. He was really, really good for a while, and then not so good. We know what he can do when he’s really good. We’ve seen it. So we want to get him back there.” – Davey Martinez

2023 analysis: To call Thompson’s season a roller coaster is underselling it. Unless you’ve ever been on a roller coaster that climbs beyond the edge of the stratosphere and then plummets below sea level. Break down his season by month, and you’ll find an ERA that was either below 2.00 or above 7.00, nothing in between.

Things started off beautifully for the right-hander, who threw 10 games in April had allowed two earned runs with a 17-to-1 strikeout-to-walk ratio. Six of those 10 appearances lasted two or more innings, culminating with a three-inning save in New York.

And then it all fell apart in May. Thompson was scored upon in eight of his next 12 outings, walking eight while striking out only seven, prompting Martinez to remove him from the high-leverage situations he thrived in prior to that point. He figured things out in a lower-pressure role in July, allowing just one earned run in 12 games. But July was once again a mess, with eight runs allowed and 17 batters put on base in only eight innings of work.

The Nats placed Thompson on the 15-day injured list Aug. 2 with a left knee contusion, giving him some time to get healthy and fix his mechanics. He returned three weeks later, but the results remained less-than-ideal: nine runs and 15 hits allowed in only 6 2/3 innings. And so, come Sept. 13, the team decided to send him down to Triple-A Rochester, where he finished out a wildly erratic season.

2024 outlook: When he’s on, Thompson is a nearly unhittable reliever, with a heavy sinker that induces ground balls at a rate (50.6 percent) well above the major league average (44.6 percent) and a sharp-breaking slider that opponents barely touched (.140 batting average, zero extra-base hits).

But as the Nationals so painfully saw this year, Thompson wasn’t on nearly enough. And when he was off, it was easy to see why: Altered mechanics. He’s never been one to reach way back as he delivers a pitch, but his short-arm action gets especially short when he’s not right. That leads to erratic command, a spike in walks and an ability to get ahead of hitters and turn to that slider to put them away.

The Nats were able to work with Thompson on the fly to correct the problem once this season. They couldn’t get him to fix it a second time later in the summer, so they ultimately decided to send him to Triple-A and hope he could rediscover his form there, away from the spotlight.

What does that mean for 2024? They should give the right-hander another chance to make the club out of spring training. But for him to stick, he’s going to have to prove he can either maintain his mechanics, or else learn how to get by when he’s not 100 percent right. The team can’t afford to go through another season of ups and downs like this one. If it happens again, they may decide it’s not worth the trouble anymore.