Julio Rodríguez has been ‘very, very aggressive’ lately. Is it working?

Ahead of the first Mariners-Red Sox game in 2024, Boston pitching coach Andrew Bailey had a blunt scouting report of Mariners slugger Julio Rodríguez.

“Julio Rodríguez: very, very aggressive,” Bailey said. “All he wants is the ball in the middle. Anything middle — ‘cambio’ (changeup) middle, slider middle — that’s all he can hit.”

Bailey’s comments came during a typical pregame scouting rundown with the Red Sox’s starting pitcher, Brayan Bello, and they were captured by a Netflix camera crew that followed the Red Sox throughout the 2024 season.

The result was a series called “The Clubhouse: A Year With The Red Sox” that debuted on Netflix in April. One scene in the first episode included part of Bailey’s scouting report of the Mariners’ lineup before opening day in Seattle, offering unfiltered insight into an opposing team’s matchup strategy.

More than a year later, in the Red Sox’s return to T-Mobile Park this week, Boston’s pitching plan with Rodríguez looks much the same: In short, don’t give him anything to hit.

In the 2024 game, Rodríguez hit a double to right field after Bello left a hanging slider over the middle of the plate.

On Monday night, in the series opener, Rodríguez went 0 for 4 with two strikeouts in Boston’s 2-0 victory.

In April, Rodríguez had a productive series at Boston’s Fenway Park, with four hits, a double and two RBI in 14 at-bats. Historically, though, Rodríguez has not hit Boston pitching well, posting a .220 batting average with .574 OPS in 21 career games, with a 30-to-3 strikeout-to-walk ratio in 94 plate appearances against the Red Sox.

This season, Rodríguez ranks among baseball’s most valuable outfielders as measured by Baseball Reference WAR, and offensively he has had the best first half of his four-year career, with 10 homers, a .257 average and a .732 OPS. There’s a compelling case to be made that he deserves an All-Star selection after missing out last season.

“He’s on pace for a 30-homer, five-and-a-half win season, so it’s tough to complain about what he’s not doing,” Mariners president of baseball operations Jerry Dipoto said on MLB Network this week. “You just really look forward to what the end product look likes for him.”

The 2022 AL Rookie of the Year has proven to be a second-half hitter — something the Mariners have relied on the past couple years — but there are some underlying data points in his profile this season to wonder if that second-half surge will happen again.

Notably, Rodríguez’s “very, very aggressive” reputation has ratcheted up another level. He’s swinging at 57% of all pitches, the sixth-highest rate in the majors, and at 71.3% of all first pitches he sees, one of the game’s highest rates.

That, he explained recently, is largely by design. He doesn’t want to let the pitcher get too comfortable in any given at-bat, and that approach has produced some strong results so far: He’s hitting .354 with half of his home runs and a 1.025 OPS when he puts the first pitch in play.

“Not being afraid,” he said. “Just trusting yourself, trusting your ability and that your eyes are going to recognize something in the zone. And be ready to go. And just kind of making them uncomfortable, too. Like, know that I’m going to be looking to swing.”

In working closely with Edgar Martinez since last August, Rodríguez has cut down his strikeout rate considerably — to 20.1%, below the league average of 22% this year. But that strikeout improvement has come with a trade-off: weaker contact.

Rodríguez’s average exit velocity through the first 71 games is down to a career-low 90.4 mph, a notable decline from his 2023 exit velo (92.7 mph).

His 42.2% hard-hit rate, via Baseball Savant, is well below his career average of 49.2%, and his ground ball rate is at a career-high 48.4% (up from 44.3% last season).

“Part of it is just the evolution of Julio,” Dipoto said. “He wants to be a complete hitter and every year he tries to pick up something new that he hadn’t done before. He’s playing his 24-year-old season. I’ve said this before, our expectations of Julio are sky-high for a reason. He’s got amazing tools. He’s a hard-worker. He shows up and he does big things. …

“He’s trying to figure out who he is. He doesn’t just want to be a power hitter. He wants to be a better hitter. He wants to reduce the strikeouts. Periodically throughout this season, we’ve seen higher walk rates … but the one thing that’s been pretty standard with Julio: July, August and September are the months when he really rolls, and that’s when you see the power. And I think we’ll see it again.”