This is a series of evaluations that will be done this offseason on every player that closed the season on the 40-man roster for the Minnesota Twins, with one appearing every weekday from now until each player has been evaluated. The plan is to start with Mr. Albers and move all the way through the pitchers, then to the catchers, infielders, outfielders and finally those listed as designated hitters on the club’s official MLB.com roster. That means we’ll wrap it up with Miguel Sano sometime before the season starts.

Name : Michael Tonkin

2016 Role : Mostly low-leverage reliever who recorded more than four outs in 24 of 65 appearances after working late innings in the minors. It was not an ideal fit, though he had extended stretches where he quietly pitched very well.

Expected 2017 Role : Assuming he makes the team — which is not 100 percent but rather likely — he’ll probably work closer to middle relief than long relief. It should suit him better.

MLB Stats : 5.02 ERA (4.40 FIP) in 71.2 innings, 10 K/9, 3.0 BB/9, 1.6 HR/9, 0.1 fWAR.

MiLB Stats : N/A

Contract Status : Eligible for free agency after 2020.

2016 Lowdown:

The numbers will tell you Tonkin didn’t have a great season, and for the most part, they aren’t lying. Tonkin was far too prone to home runs — which especially hurts as a fly ball guy — and his 5.02 ERA is only slightly lying when it suggests how effective he was in 2016. In this space before, we’ve debated the merits to having brought Tonkin up for a longer look earlier than 2016, but it never really happened. Sure, he came into the season having thrown 53.2 fairly solid big-league innings, but over three seasons that’s far from substantive.

As a result, Tonkin was out of options in 2016, and like a few others on the team was shoehorned into a role he was ill equipped for. Tonkin had basically been a one-inning reliever since his Arizona Fall League stint in 2012, yet was coming into this past season as the long guy. To Tonkin’s credit, it didn’t start out poorly. Through two months, he had an ERA of 2.96 with a 30-9 K/BB ratio in 24.1 innings. That’s pretty dang solid, low-leverage work be damned.

Tonkin had a bit of a hiccup in June — 5.93 ERA, .902 OPS against — before recovering in July (3.29, .669), and even to that point was having a fairly solid season. He had a 3.83 ERA through 51.2 innings — roughly mirroring his previous MLB experience — with a 62-14 K/BB ratio in 51.2 innings. The eight home runs were a pretty severe blemish on his record, but otherwise he looked like a passable middle reliever.

But from that point on, Tonkin looks like he was hit by a freight train.

Over the final two months, Tonkin compiled an 8.10 ERA over 20 innings with 18 strikeouts and 10 walks. He allowed five home runs and six of his appearances down the stretch resulted in multiple earned runs allowed — an ERA killer for any reliever.

The first inclination might be that Tonkin was overused, though that may be hard to prove. He threw 71.2 innings in 65 appearances in 2016 after totaling 59 appearances and 64.1 innings the year before across two levels. The year before that, Tonkin threw 64 innings between the Twins and Red Wings in 64 appearances, so maybe there isn’t a fit there. More likely, if there was overuse, it was the number of innings in specific outings rather than appearances or the innings accumulating. At least that makes the most sense to this writer, especially since Tonkin profiles as a max-effort reliever whose primary talent or skill is his velocity.

Let’s head over to Brooks Baseball to see if we can see anything unusual over there.

Up until Aug. 1, Tonkin was averaging somewhere between 94 and 95 mph on his fastball. It’s unclear where exactly he lands, because Brooks lists him as throwing a four-seamer and a sinker. Fangraphs, on the other hand, calls them all two-seamers. I know this, because Tonkin has told me on multiple occasions that he doesn’t throw a two-seamer at all. “Almost never,” Tonkin said late last season. “I’ve maybe thrown a couple two-seamers all season, if that.” If you hear some chatter about Tonkin’s fastball being straight, that’s nonsense.

It’s quite the opposite; the four-seamer moves so much it fools the PITCHf/x algorithm into thinking it’s a two-seamer.

We can approximate about a 94.7 mph velocity based on frequency the Brooks algorithm tracked each pitch. Tonkin was also getting a fairly solid 15.1 percent whiff rate on his slider before Aug. 1. Flipping the dial doesn’t tell us much from Aug. 1 on. Tonkin’s right around 94.6 mph the rest of the way, while the slider added that leftover tick from the heater. The whiff rate on the slider cratered a little bit, but only down to a still pretty solid 13.7 percent.

As a result, we’re left without much of a concrete explanation as to why Tonkin faltered so badly down the stretch. He was still throwing as hard as ever with roughly the same slider, yet completely fell apart.

That doesn’t mean there aren’t things to like with Tonkin, however. He still throws plenty hard with a good slider, and if he could keep the ball in the ballpark — which hasn’t been a problem for him elsewhere, so there’s hope — he could still carve out a role as a solid middle reliever. His groundball rate is completely baffling. He induced grounders at a 57.1 percent rate in 2015, a 34.1 percent rate in 2016 and has a career rate of 40.7 percent.

His month-by-month rates from 2016 are just wacky, too:

April – 21.4 percent

May – 26.7 percent

June – 46.3 percent

July – 42.9 percent

August – 34 percent

September – 25 percent

Somehow, that equates to a 34.2 percent groundball rate in the first half, and a 34 percent rate in the second. How? It makes no sense. There also isn’t much in terms of a correlation between groundball rate and HR/FB rate. To dumb that down as much as possible, one might think inducing the most grounders would lead to better rates of home run suppression on balls put in the air — and with Tonkin there was simply no proof of that in 2016.

In other words, Tonkin’s 2016 is baffling, and it’s hard to know exactly how to break it down. There’s still ample talent here, and he doesn’t have enough of a track record where he can be confidently written off, but it’s probably not likely he’s in the “closer-in-waiting” discussion moving forward. But if he can provide the Twins with solid relief in the sixth and seventh innings this season, he could be a useful arm out there. For instance, watch the video at the top of the post. A 96 mph heater with that kind of run is awesome.

Grade: C+. Had long stretches where he was very useful and was used in a totally different role than ever before, but ultimately the numbers paint a picture of a guy who was overworked and unraveled late.