Earlier in the day, the Boston Red Sox made a franchise-altering move by acquiring three-time All-Star and Silver Slugger Award winner Adley Rutschman. 

Yet after a key addition on offense the Boston faithful had longed for, it needed to shore up its innings on the mound.

With Ace Garrett Crochet out and limited to very few innings in a potential return, left-hander Erik Miller seemed like a perfect fit alongside Brayan Bello and veteran closer Aroldis Chapman to fortify the No. 4 bullpen in ERA pre-deadline.

So far with the Red Sox, Miller has put together 13 appearances, giving up two runs (0.68 ERA) and striking out 24. Given the uncertainty of Crochet and Bello’s inability to pitch in the first inning, Miller may be the perfect opener; in ten appearances with the Giants, he has a 0.84 ERA. 

HOW LONG IS THIS PRODUCTION SUSTAINABLE? 

Most find the biggest challenge isn't being sent off by the organization that developed you, shipping equipment, finding a flight, or getting your profile to a new staff; it's saying goodbye to the personnel, city, and clubhouses that shaped your career to that point. 

Boston is known for having one of the best, but also toughest, fan bases in sports. Simply put, a player gets rewarded for doing well, but may hear their name in unwanted conversations for struggling. 

Thus far, this hasn't affected Miller at all, and while the electricity, raw stuff, and having Shohei Ohtani’s number have always been consistent, he's had his ups and downs through his journey. 

According to Fangraphs, Miller has a historically high walk rate of 12.3% to 15.6% when he struggles to command the strike zone. 

Miller’s chase rate only ranks in the 24th percentile on Baseball Savant, with walks in the eighth percentile. Despite having good profiles on pitches, hitters have a fairly easy time laying off anything out of the zone. 

On the bright side, practically every other category on his Savant page is Red Sox red, meaning nearly everything is above average. 

Miller’s opponent expected batting average, whiff, and strikeout rate all rank in the 97th percentile, while average exit velo and hard-hit percentage rank in the 99th, comedically close to the best possible grading. 

WHY BOSTON?

Many teams were after Miller, but depending on who you ask, Boston may have put together the best package, offering former top 15 prospect Marcelo Mayer, in part because of familiarity. 

In 2023, the Giants announced the hiring of longtime manager and former MLB catcher Bob Melvin, just two years after Gabe Kapler led the team to a miraculous 107 wins in 2021, only to lose to the Dodgers in the NLDS. 

Kapler and his staff are known for being analytically based, playing matchups, platooning based on hitters' splits at the plate, and relying on advanced metrics to guide on-field instruction. 

Melvin, on the other hand, leaned toward the old-school side of managerial style, and no matter the situation, it's not uncommon to see a whole new staff with a new name at the helm, with pitching coach Andrew Bailey departing to Boston. 

Bailey was the pitching coach in San Francisco for four seasons, and while he didn't see Miller make his MLB debut, he was clearly recognized as a stabilizing lefty with elite stuff.

With the Giants, Bailey’s bullpen was among the best in baseball, posting a 3.80 ERA with the fewest home runs (525) and walks allowed (403) in his time in the Bay. 

Therefore, it is no surprise that Boston has the fourth-lowest ERA in Major League Baseball this season (3.60), behind the Milwaukee Brewers (3.54), Atlanta Braves (3.57) and rival New York Yankees (3.23). 

Bailey also broke down the mental and informational side of the game in “The Clubhouse,” a Netflix series that took fans behind the scenes into the daily lives of players, coaches, general managers and reporters.

"This game can snowball on you incredibly fast if you let it. The mental grind here is real,” Bailey said on the show. “My job isn't just to look at a data sheet; it’s to give these guys a concrete plan so that when they step onto that mound, there’s zero room left for doubt. When you have structure, you can go compete.” 

A lack of production on the field can result from a lack of structure off the field. 

Bailey excels at putting his arms in the best possible position to succeed, no matter the occasion. 

WHAT'S IN IT FOR THE GIANTS? 

The Giants currently sit 23 games under .500, in part due to the lack of experience in the bullpen. 

Before last year's trade deadline, San Francisco lost five games in a row and 11 of 13, leading them to sell just over a month after trading for two-time Silver Slugger Rafael Devers. 

Many considered the 2025 deadline successful. 

Right-handed reliever Tyler Rogers snatched up a young outfielder with upside in Drew Gilbert, reliever Jose Butto, and a highly touted prospect in Blade Tidwell, who has started to find a groove in the show. 

Closer Camilo Doval was acquired by the Yankees and delivered two prospects who instantly hit the Giants' top 30 in Jesus Rodriguez and Parks Harber. 

The Giants certainly delivered for their future, and with star reliever Randy Rodriguez at the back of the bullpen, the moves can be justified. Unfortunately, just six weeks after making his first All-Star Game appearance, Rodriguez needed Tommy John surgery.

With few moves in the offseason to bolster the bullpen and three rotation spots filled by arms with a history of uncertainty on the field in Adrian Houser and Tyler Mahle, it's fair to say the ship sailed from the start. 

Jump ahead to 2026, and it’s another season and another August of attempting to sell off every asset possible, including the team’s core of Devers, Matt Chapman and Willy Adames. 

The core may have made it through, but several pieces were moved. 

The Giants' first homegrown All-Star outfielder in 38 years, Heliot Ramos, was dealt to the Yankees. 

Projected National League batting champion Luis Arraez landed in Philadelphia with the Phillies, while Tyler Mahle joined the party in Atlanta. 

An interdivision trade was also completed, sending Robbie Ray to the Padres, and of course Miller to Boston. 

Again, the return this year was elite: Henry Lalane (acquired via NYY) is a 6-foot-8 left-hander with a power fastball, and Ramon Marquez (acquired via PHI) is a top 100 prospect, according to MLB Pipeline, featuring a 70-grade changeup. 

Prospect rankings are certainly fun to look at, and for Giants fans, having five in the top 100 is definitely something to eagerly await. 

Nonetheless, no matter how high a player is valued, there's no guarantee it will work out in the big leagues. 

In 2018, San Francisco selected Joey Bart with the second overall pick in hopes he would be able to succeed Buster Posey upon his arrival, and it got the exact opposite.

No. 1 and top-25 MLB prospect Marco Luciano struggled to find his footing in the majors, with a lack of defense and an inability to slug at the plate leading to his being designated for assignment. 

Now, with Bryce Eldridge living up to the Phenom expectations early in his career, the Giants will have another opportunity to try and develop a middle infielder with Mayer. 

Much like Luciano, Mayer couldn't stay on the field in Boston, but in his case, it was due to injuries. After being sidelined again this past year, the Red Sox decided it was time to move on. 

The tall, smooth-swinging lefty rose through Boston's organization alongside star outfielder Roman Anthony and utility Kristian Campbell, the proclaimed future in Fenway. 

Mayer profiles as a defensive-first diamond athlete, with low chase rates at the plate and the ability to hit the ball hard. 

"His raw baseball skills are off the charts; it looks like the game just comes easy for him, and I love him as a person,” Bailey said. “He'll take that opportunity and run with it; I'm excited to see where Marcelo's career takes him." 

A month later, Mayer still hasn't played for San Francisco after being sidelined during a rehab assignment from a right foot bone bruise. 

However, a change of scenery could be all it takes to get Mayer on the right track, and in a lost season with injuries to Adames and Chapman, why not give him a shot if he can get on the field? 

The Giants infield will be full next season, but if Mayer makes a push for a starting position, we could see utility Casey Schmitt move back to the outfield to open up a spot. 

Yet, in limited time on the dirt this year, he reminded everyone why he won a Gold Glove in the minor leagues. 

Despite being completely out of the postseason field, San Francisco has an interesting last few weeks before the season ends, with plenty of opportunities being given internally in hopes that some will step up and earn a spot on the MLB roster for 2027.