Sergio Estrada-Imagn Images

First impressions can prove to be fleeting in baseball, but it’s still better to make a good one than a poor one. And as first impressions go, Boston Red Sox rookie Connelly Early’s was absolutely dynamite. Throwing five innings in his debut, Early whiffed 11 A’s batters, with a single walk as a minor demerit, and exited the game with a 5-0 lead that was never threatened.

Even in a strikeout-happy era, striking out 11 of 21 batters faced is an impressive feat. In fact, 11 strikeouts tied Don Aase for the most by a Red Sox pitcher in a major league debut, and Early’s mark is the most ever in a five-inning rookie debut. And it wasn’t done in a particularly easy environment. The Red Sox are a probable playoff team fighting to win the AL East and grab an extremely valuable first-round bye, which would give injured players like Roman Anthony more time to return. And while the Athletics have one of the worst records in the American League, the responsibility for that plight falls mostly on the pitching staff, not the lineup Early faced. The A’s have a 105 wRC+ on the season, well short of elite, but in the solidly above-average range. Nor did Early benefit from a Bad Team September Lineup © situation, with the A’s playing all five of their full-timers who have an OPS above .800.

So how did he do it? Sometimes rookie pitchers simplify their repertoire somewhat while they’re getting adjusted to the majors, but Early threw five different pitches at least 10 times, and got at least three swings and misses on each of them, totaling 19 for the game. His most hittable pitch on Tuesday, his changeup, still had a respectable 70% contact rate, about league average for changeups (70.5%). And with the exception of his sinker, which he only offered up against lefties, he didn’t aggressively limit his toolset based on the platoon advantage, either. (For more on Early’s stuff, I can’t do better or find a more fitting piece for you to read than David Laurila’s May profile of the southpaw.)

Early’s whiff rate doesn’t even need the “major league debut” qualifier to be impressive. A 58.7% contact rate is terrific for any starter, checking in at just about the 97th percentile for all starts in 2025 (135th out of 4,350 starts).

Even after the Red Sox decided to aggressively promote Payton Tolle at the end of last month, I was still surprised that Early was called up from Triple-A so quickly, having made just six starts at Worcester. But in hindsight, perhaps I shouldn’t have been, whifferrific debut or no. While the number of games is still a relatively small sample, there isn’t a lot of fakery possible in whiff rate, and Early’s whiff rate at Triple-A improved rapidly over his last four appearances prior to his promotion. Having your opponents’ contact rate drop from 81% to 73% to 70% to 57% is an impressive short-term progression.

Now, there are still areas where Early could stand to improve, and doing so would help to maintain the love-at-first-sight feeling that many Red Sox fans are no doubt enjoying today. Command has been a concern during Early’s time as a prospect, and there were some signs of that on Tuesday. The A’s didn’t punish a handful of really hittable middle-middle four-seamers, and especially in the first inning, his control wasn’t quite up to his usual standards. The A’s quite consistently laid off curveballs that weren’t in a narrow range at or below the bottom edge of the zone, and at least a few of those locations might not have been intentional on Early’s part.

Early didn’t get an official ZiPS projections coming into the season, an oversight on my part since he did get eight starts for Double-A Portland last year. But if he had, and I had been able to include his 2025 minor league starts, he would have made the back end of my rundown of the pitchers with the most improved 2026 projections.

Success from Early and Tolle opens up a lot more options for the Red Sox in the playoffs. Tanner Houck’s elbow surgery ended any slim chance he had of returning late in the year, and Kutter Crawford’s season has been over for a while now. Dustin May is out with elbow neuritis, and while he could return, his status is uncertain. Without the rookie call-ups, Boston’s October rotation would feature an ace in Garrett Crochet, and two solid starters in Brayan Bello and Lucas Giolito. That isn’t a bad group, but it’s sorely missing depth should the Red Sox need to turn to a fourth starter or fill in for an injury. If Early and Tolle both conclusively demonstrate they belong in the majors down the stretch — and I think there’s a very good chance they will — the postseason staff looks a lot less like Swiss cheese.

ZiPS assesses rotations differently in the playoffs than it does in the regular season, as you get more innings from the top of the rotation. If you remove Early and Tolle from consideration, ZiPS projects the Red Sox to have the 19th-best rotation in baseball when you force the computer into “playoff mode.” With Early and Tolle, they improve to 11th best, and several of the teams with better staffs are either set to miss the playoffs entirely (Twins, Pirates), or at least look like long shots (Reds).

Will Connelly Early continue to rack up double-digit whiffs? Probably not. But his 2025 season has made a solid case for him to be in Boston’s rotation long-term, even without knowing about his big league debut. And that big league debut was one of the best I’ve seen in a very long time.