After a second-half slump and option decline, Shota Imanaga's revamped mechanics and revitalized fastball are silencing doubters, re-establishing his ace status.
There were question marks about which version of Shota Imanaga would show up this season.
In Imanaga's 2024 rookie season, he was a top starting pitcher in the league. He finished with a 2.91 ERA, a 1.021 WHIP, a fourth-place finish in the National League Rookie of the Year voting, and a fifth-place finish in the National League Cy Young voting.
In 2025, however, Imanaga failed to follow up on his successful rookie campaign. The left-hander was one of the worst starting pitchers in the second half, as he carried a 5.17 ERA and allowed 20 homers after the All-Star break.
Those second-half struggles led the Chicago Cubs to decline his three-year, $57.75 million option in the offseason. The Cubs didn’t seem on board with committing long-term money to him, given how he looked in the final three months of the season.
However, those struggles appear to be in the past. Imanaga is fully healthy again after dealing with a hamstring injury last year, and the 32-year-old is pitching like a top pitcher in baseball once again.
Imanaga has a 2.45 ERA, a 0.773 WHIP, and 31 strikeouts across his four starts this season. He has struck out 20 batters over his last two outings and just put together one of the most dominant starts of his career in Wednesday’s win over the Phillies.
The southpaw threw six innings of one-run ball with 11 strikeouts in that game. He really settled in after allowing a first-inning home run to Trea Turner. His 11 strikeouts tied his career-high, and he was missing bats left and right in this outing.
Imanaga also induced a career-high 26 whiffs against the Phillies. Those 26 swings-and-misses were the most by a starter this season and were the most whiffs by a Cubs pitcher in the pitch-tracking era since Yu Darvish’s 26 whiffs back on August 23, 2020.
This has been a fantastic start to the season for Imanaga. He looks like a completely different pitcher from last year and appears to be returning to his rookie-year form.
But what has been the difference for Imanaga in the early going? What has changed from his second-half struggles in 2025?
There are a couple of major differences for Imanaga from last season to this season. His arm angle has risen by 4°, he’s generating more swing-and-miss on his splitter (44.3% whiff rate) and sweeper (44.4% whiff rate), and his strikeout rate is up (37.8%).
The biggest difference for Imanaga in the early going, though, is that his fastball is more lively. Last season, he averaged just 90.8 mph on his four-seam fastball, and his -9 Fastball Run Value ranked in the bottom 10% of the league among all pitchers.
This year, both of those numbers are up. Imanaga is averaging 92 mph on his four-seam fastball across his first four starts (up 1.2 mph from 2025), and his 5 Fastball Run Value ranks in the top 2% of the league through the first few weeks.
When Imanaga is at his best, it’s because of his fastball. He’s able to lead with his four-seamer, and then his offspeed stuff (splitter and sweeper) becomes more dangerous. Opposing hitters are batting just .133 against his fastball to begin the season.
While it might be too early to say that Imanaga is officially back, it’s certainly trending that way.