Detroit’s new-look bullpen should be even newer-look in September

Coming into the MLB Trade Deadline, Detroit’s bullpen was struggling and much maligned, for good reason. Nobody outside of Will Vest had been a consistent, positive presence throughout the season, and their overall inconsistency meant the unit never really clicked all at once. It felt like as soon as Tyler Holton started piecing things together, Tommy Kahnle forgot gave up home runs in bunches or Brant Hurter lost the zone entirely, and the stats bear that out.

At the time of the deadline, Detroit ranked 19th in ERA and 20th in FIP among all relief units. Their measly 12% K-BB% ranked 22nd. Thanks to Vest’s strong season, they did rank well in Win Probability Added (13th) and Blown Saves (24th, where lower is better), but one man, a unit does not make. Thankfully, Scott Harris took note, and at the Trade Deadline, added several high-quality relievers to the mix… checks notes. Oh wait. Kyle Finnegan and Rafael Montero. Hang on.

Ok, so the Tigers didn’t exactly go whole-hog at the deadline, but the bullpen has felt better of late. Big picture, the results have gotten a whole lot better. Since the deadline, Detroit’s pen is 2nd in ERA! Problem solved, right!

If only.

Their FIP is an unsightly 25th, their K-BB% 28th, they’ve even blown 4 more saves, dropping them into a five-way tie for sixth least in the league. ERA aside, it hasn’t been that pretty.

What’s amusing is that the new additions haven’t really been the problem. Kyle Finnegan has been nails (ERA of 0, FIP of 1.07 with Detroit) and while Rafael Montero has been oscillating between brilliant and unwatchable, his FIP is a near-even match for Detroit’s collective FIP after the break. For now, the problems are inside the house.

Only 2 Tigers relievers have a FIP below 4.00 since the trade deadline; the aforementioned Finnegan and –checks notes– Sawyer Gipson-Long? Relax, it’s 2 innings. Anyways, here’s the whole table, and note that Melton’s stats are only being counted for his relief appearances; things are rosier (1.15 ERA, 3.83 FIP) if we include the start against Chicago.

That’s rather unappealing to look at; entirely too many 4s and 5s in the middle of that list, to say nothing of the actual problems at the bottom. Things aren’t exactly as awful as they seem, but the facts are facts: pitchers in this pen either get strikeouts and walks, or neither, or sometimes just walks, and that’s a scary tightrope to walk. They collectively rank 23rd best in strikeout percentage in the month of August.

The good news takes two large shapes. Firstly, these sample sizes are inherently miniscule. FIP doesn’t really become informative until inning totals approach 100, and ours are close to 10, so take that as you will. For example, Vest’s post-deadline FIP was 3.40 until his meltdown on the 26th, which isn’t refected in his ERA because it was extra innings. When one rough inning can skew things so drastically (20% change!), the sample is probably not worth caring about too much.

The second is that most of the names on this leaderboard are unlikely to impact the playoffs. 5 of the bottom 10 are off the active roster right now, and at least 4 of those are long-shots at best for a playoff bullpen. There’s a fairly strong argument that Heuer, for example, is entirely inconsequential for the rest of the season as a guy they’re mainly stashing as a project for 2026. What’s done is done, but he won’t hurt us anymore, so it’s largely ok. Holton is the only truly critical reliever to give any cause for concern over this stretch.

What’s really puzzling, though, is who isn’t on the active roster right now. Harris has lauded the ability to add options throughout this season and give AJ Hinch as many interesting names to use as he wants, which is all well and good, but where are Gipson-Long and Lange? For a team short on strikeouts, doesn’t it make sense to give two pitchers with strikeout rates of 25.4% and 27.2% for their careers major league reps and coaching?

To me, the best Tigers bullpen will certainly have Lange and Gipson-Long in it. Their minor league numbers have been good to great throughout their rehabs and their stuff all seemed intact in their brief MLB samples. Neither is a relief ace in the hole, but tuning those two up certainly seems higher priority than seeing what Sommers or even Kahnle can put together over the next 4 weeks. Open tryouts are all well and good, but there isn’t that much time left in the season.

At least Sommers has a good season in the upper minors and the fact that he’s a rookie to recommend trying him a little longer to see if he can point aside some rookie jitters and show more of the good command he had with Erie and Toledo. With Hurter injured, the Tigers are really thin in terms of left-handed options. However, Kahnle has had all season to find his strikeout touch and it just isn’t happening. Beyond them the options for call-ups come down to Jose Urquidy, whose rehab window endson September 2, with an option for the Tigers to extend that by 10 days, Keider Montero, and possibly right-hander Paul Sewald, assuming his shoulder cooperates.

At the end of the day, the bullpen in front of us today is pretty different from the one we saw prior to the deadline. It’s likely very different than the one we will see come October as well. Tarik Skubal is once again the only truly dependable starter down the stretch, so expect Pitching Chaos 2.0. Hinch will mix, match, swap, change, guess, and magic his way around opposing lineups the best he can with the other 12 pitchers he has at his disposal, without necessarily giving a normal “start” to any of Jack Flaherty, Charlie Morton, or Casey Mize. If one other arm, mostly likely Melton or Holton, can anchor the back of the pen with Vest and Finnegan, freeing the medium leverage arms for the most favorable matchups to bridge between starters and their best relievers, the Tigers should be in better shape than it seems right now.