2023 Atlanta Braves Season in Review: Michael Tonkin

In only feels right to start this review with a little self deprecation. Way back in late March, this was my prediction for what Michael Tonkin contribute to the 2023 team:

Yes, that’s me predicting Michael Tonkin would be designated for assignment a week into the season and most likely never heard from again. What an idiot. As you know by now that is not what happened to Tonkin in 2023. Not only was he not DFA’d in the first week, he was never DFA’d at all, and went from basically an unknown to a mainstay in the Braves bullpen in 2023.

How Acquired

Tonkin has been at this whole baseball thing for a while. He was originally drafted by the Minnesota Twins back in 2008, you know, three years before Freddie Freeman’s first season in Atlanta. He was a teenager, just out of high school, and he took the long way around the Twins minor league system, making an appearance for just about every minor league team they have. He finally got called up in 2013, and camped out as a generally-present but relatively low leverage reliever in Minnesota for the next five years before getting released in 2017. (Over five seasons and 146 ⁄₃ innings, he had a 105 ERA-, 108 FIP-, and 98 xFIP-, which are not really numbers for any reliever but a mop-up guy, but there we are.)

Tonkin then had a successful stint in Japan which earned him a couple more minor league deals stateside in 2019 and 2020, but he didn’t stick with his new organizations. In January 2022, Tonkin signed a minor league deal with Atlanta, and put together an outstanding year for Gwinnett, which put him on the team’s radar as a possible big league bullpen option for 2023 and earned him his Spring Training invite.

What were the expectations?

It had been a long, long time since Tonkin saw a major league field prior to 2023; over six years, in fact. As a result, any expectation north of “hope he just survives” was probably too high. But to be fair to him, his prior pitching was replacement level and not awful, and considering he had worked some long relief before, it wasn’t unreasonable to assume he could be a major league long man or mop-up guy somewhere.

Upon his invite to Spring Training, the Braves were just looking for someone to compete for a spot and potentially provide some lower leverage innings, possibly in bulk. No one gave him a real shot to actually make the team, and even if he did, no one thought he'd stay up very long.

2023 Results

As our own Scott Coleman pointed out on a recent episode of the Battery Power Podcast, Tonkin ended up pitching the fourth-most innings of any pitcher on the team in 2023, partly because of serious injuries to 40 percent of the starting rotation, and partly because he was the bulk guy on a great team and there were plenty of blowouts to mop up.

Tonkin ended the year with 80 innings pitched, a 4.28 ERA, a 3.85 xERA, a 4.43 FIP and a 4.30 xFIP. (Those are a 96 ERA-, 103 FIP-, and 98 xFIP-.) All of those are basically right in line with what his career numbers were with Minnesota, oh so many years ago. Over those 80 innings, he struck out 75 hitters and walked 23 of them, for a strong 3:1 strikeout to walk ratio, but didn’t keep the ball on the ground too well, hence the middling xFIP.

Tonkin also finished with a neutral WPA (-0.01) and a mediocre 11 shutdowns to eight meltdowns. All in all, he earned 0.1 fWAR, his third career season in six tries with positive value by that metric.

What went right?

Any time you have a fly ball-oriented pitcher, the principal; concern from an outcomes perspective is going to be HR/FB variation, because if those guys have a bad year in that regard, their whole season can go into the toilet pretty quickly. At at a HR/FB rate of 13.8 percent in 2023, Tonkin had a relatively normal season, which was not the case in some of his previous seasons with Minnesota. Truist Park can also be a place where the ball flies so only 13 homers given up over 325 batters faced was a solid number for Tonkin.

Tonkin limited free baserunners as much as reasonable could be expected. 23 walks in 80 innings, and only two bean balls added to that, meant that for the most part, hitters had to earn their trip to first when Tonkin pitched. He also had tremendous luck in avoiding infield-hits, which are mostly bad luck as they're usually weakly hit ground balls that find optimal grass to park on.

Neither of Tonkin’s pitches functioned poorly — his sinker allowed a .328 xwOBA which is pretty good as far as sinkers go, and the slider had a nice .254 xwOBA-against and a whiff rate north of 30 percent. His sinker actually functions more like a four-seamer so it’s not an ideal grip-and-motion situation, and he got into some habits of throwing it way too much here and there, but it did okay for him in the end.

Tonkin’s most epic game of the year was almost certainly May 7, against the Orioles. He had to work two extra-inning frames and gave up runs in neither, with the first scoreless frame aided by Ronald Acuña Jr.’s laser beam throw to retire the ghost runner trying to take third. He then had a much more straightforward 1-2-3 inning in the 12th to set up Michael Harris II’s walkoff hit.

What went wrong?

If you look through his Statcast profile, you see a whole lot of meh. The combination of not striking many people out and not getting many ground-balls is a rough combination to live on and you really are at the mercy of your HR/FB luck. Further, at a 90 mph average exit velocity, Tonkin isn’t exactly mastering the art of soft contact. Hitters get decent swings off of him. When you give up fly balls that don't leave the yard however, it does help your xERA, as those are fly outs if they’re not in the HR part of the HR/FB equation. Tonkin gave up a lot fly balls that didn't leave the yard, as to be expected when a guys averages 19 degrees of launch angle on his batted balls.

Tonkin is also not really a raw stuff guy either. Throwing 94 mph once meant you were at least above average in velocity, but not in today’s game, and especially out of the bullpen. Hitters look at 94 like they used to look at 92 and it probably feels like a nice reprieve after seeing 98, 99, and 100 so often.

All this together makes Tonkin a useful piece for getting through a six-month season, but not much more than that. That’s why, perhaps unsurprisingly, one of Tonkin’s worst games of the year came in an irrelevant situation on October 1: he turned an 8-7 lead in the ninth into a 10-8 loss by walking in the tying run and then giving up a two-run single. His job there, though, was just to soak innings before the postseason, and that’s what he did.

Not that he was always money when it mattered, either. The Braves occasionally paid the price for using him in higher leverage, like this game on May 1 when he relieved Charlie Morton with a one-run lead in the sixth, just because he was apparently the designated long guy. After a flyout, he gave up the lead and what eventually turned out to be the game here:

Which makes the fact that he came into NLDS Game 3 because he could “warm up quicky” seem like something from a satire, and not something that actually happened. But it did.

2024 outlook

Tonkin’s solid, though unspectacular season, at least should've had the Braves considering tendering him a contract for 2024, as Tonkin was in his first year of arbitration eligibility and only was going to cost around $1M for next season. The problem for Tonkin is apparently the Braves are using this offseason to make wholesale changes to the depth of their roster and the makeup of their bullpen. Atlanta already had Raisel Iglesias and A.J. Minter under team control and making real money. Then they re-signed Pierce Johnson and Joe Jimenez before free agency opened, and since then have traded for Aaron Bummer and signed Reynaldo Lopez as a free agent. Plus they have Tyler Matzek coming back, at least in theory.

With such dramatic changes to the bullpen and a clear focus on stuff and velocity, Tonkin’s spot got squeezed out pretty quick, and he got the bad news last Friday:

Tonkin is now a free agent and free to sign with any team. It would not surprise anyone to see Tonkin back with the Braves next year on a minor league deal, but he’ll almost certainly look to see if he can find a major league deal somewhere first before circling back. It’s not a slam dunk that he warrants one given his 2023 performance, but a team could also do worse at rounding out its bullpen.

For next year, Steamer sees Tonkin having a very similar, in fact somewhat better season as he did this year, with a 4.29 FIP and 0.2 WAR in 46 innings. There should be plenty of teams that see that as useful enough to add in a lower leverage capacity, just like the Braves did previously.