The Blue Jays need to improve the offence this winter. But even if Toronto nails a few off-season offensive additions, this lineup isn’t going to be the ’27 Yankees. Toronto’s offensive upside is probably similar to the 2023 team that finished 11th in team OPS and 16th in runs scored.

So, if the 2025 Jays are going to scratch and claw their way back to the postseason, it’s going to come on the back of the rotation. Luckily, things are looking up for the starting five at the end of this season:

By ERA, the Blue Jays’ rotation is the best in baseball in September. There are some signs that Toronto’s 2.27 rotation ERA this month isn’t entirely deserved (ninth-lowest wOBA against, 17th-lowest FIP), but this is still a huge step up from the starting production the Jays have had all season.

Considering Toronto’s starting rotation had a league-average ERA mark of 4.09 in the previous five months, this ascendance (back) to elite status is encouraging. Kevin Gausman, Yariel Rodriguez, and José Berríos all had their best months of the season in September.

This level of starting pitching is exactly what Ross Atkins and the Jays front office was hoping for all season (not when they were already eliminated from playoff contention). The Jays had the third-lowest rotation ERA in baseball in 2023 and leaned on that rotation for the fifth-most innings pitched — and tried to repeat that recipe this season. With a strong finish to the season, maybe Toronto’s rotation can be the squad’s engine once again in 2025.

We all know, by now, about Francis’ new splitter. But a lot more has gone right for Toronto’s rotation this month. Here are some notes on what, specifically, has helped the Jays’ starting five form September’s best rotation:

During his mid-season struggles, Berríos went away from his slurve, throwing it around 25% from June to August. His 31.3% usage of the pitch in September is much more in line with his 2023 standard, and the pitch has been more effective, too, posting a season-high 37.5% swing-and-miss rate.

After posting whiff-rates near 50% on his splitter the last few seasons, Gausman’s big weapon became far less effective to start the year. Before September, Gausman’s splitter didn’t register a swing-and-miss rate over 40%. This month, he broke the mark for the first time in 2024.

Gausman has clearly been toying with the release point on the pitch the last few months and has also thrown the splitter a touch harder in September, potentially contributing to this uptick in effectiveness.

Rodriguez can throw five pitches and he’s used them as a pretty even mix through most of the season. But in September, YRod has become a mainly sinker/slider pitcher to great effect. While his four-seamer still made up 31.9% of his usage this month, the sinker/slider comprised nearly 50% of all his deliveries.

Turns out, those have been his two best pitches, too, earning expected batting averages of .201 (slider) and .116 (sinker). I’d expect him to stick with those two pitches as the core of his arsenal next season.