Giants: Who is 40-man roster prospect Joe McCarthy?

The San Francisco Giants acquired outfielder Joe McCarthy in exchange for pitching prospect Jacob Lopez at the 2019 trade deadline.

Why are we talking about San Francisco Giants prospect Joe McCarthy?

The 25-year-old currently owns a spot on the team’s 40-man roster. Despite that, he did not receive a call-up in September, and not much has been said about him since then.

After the trade, Giants team president Farhan Zaidi had modest expectations for the left-handed hitter:

The 2019 season was a lost year for McCarthy as he struggled at the plate while battling back injuries. Across 279 plate appearances, the outfielder posted a .183/.301/.328 line with seven home runs and 27 RBI. 

A season like that will generally result in a player being removed from the 40-man roster, but that was not the case with McCarthy. In fact, the general sense is that he has a stronger hold on a roster spot than several other prospects. 

In January 2019, Kiley McDaniel and Eric Longenhagen of FanGraphs ranked McCarthy as the 14th best prospect in the Tampa Bay Rays organization. The Rays farm system frequently rates as one of the better pipelines in baseball, so coming in as the team’s No. 14 prospect does not happen by accident.

Here’s the scouting report that McDaniel and Longenhagen provided at the time:

"“McCarthy might be this decade’s Nick Johnson. He has limited physical ability but exceptional secondary skills, and a concerning injury history. In college, McCarthy missed several weeks of his junior year due to back surgery, and in 2018, he had back issues again, which cost him several months. His Fall League stint ended prematurely due to a fractured hand. Amid these injuries, McCarthy has reached base at .390 career rate and climbed to Triple-A Durham. He has sufficient physical tools to hit, just not for stardom, and we expect him to be a role-playing 1B/OF who yields value on par with a low-end regular, assuming he can stay healthy”"

Despite the down year, McCarthy produced strong peripheral numbers with a 15.9 percent walk rate against a 29.7 percent strikeout rate. Throughout his professional career, he has posted a stout 13.8 percent walk rate across 1,691 plate appearances.

As a team, the Giants posted a 7.7 percent walk rate and a .302 on-base percentage in 2019. Those marks ranked as the third worst and second worst figures in the National League, respectively.

In addition to adding power to the lineup, improving the team’s on-base percentage and walk rate should be a priority heading into 2020.

A high walk rate is the type of quality that appeals to Zaidi, and McCarthy seems to have another high-profile fan in the organization as well.

In a piece that profiles Gabe Kapler‘s first month as the new manager for the Giants, Alex Pavlovic of NBC Sports Bay Area included a small nugget about the new coach’s interest in McCarthy:

"Kapler wanted a statistical breakdown of Joe McCarthy, an outfielder who came over from the Rays in a small move minutes before the trade deadline and hit just .165 in Triple-A for the Giants. Kapler also asked for McCarthy’s phone number so he could reach out and find out more about a player who doesn’t seem to be in the immediate plans for the outfield."

This could simply be due diligence on Kapler’s part as he evaluates the 40-man roster. However, it is interesting that McCarthy’s name was mentioned since little has been said about him he was acquired.

It could mean that both Zaidi and Kapler believe McCarthy still has room for development. Thus far, health concerns and injuries have stunted his growth.

With Alex Dickerson and Mike Yastrzemski, the Giants appear set on left-handed hitting outfielders. That said, McCarthy offers a little extra positional versatility with the ability to also handle first base. Unlike Dickerson, he has professional experience at center field as well.

Kapler has brought in a coaching staff well-versed in modern analytics, and one that will play a more proactive role in player development.

Despite the down year in 2019, the Giants new front office appears to like McCarthy’s offensive profile and seems to believe last season was not representative of the outfielder’s true ability.

McCarthy could become an early experiment in the new coaching staff’s developmental philosophy. While most of the players on the 40-man roster are known qualities, McCarthy remains an intriguing question mark.