Report: D-backs Sign Minor League Catcher Ronaldo Hernandez

The former Rays prospect is set to join the D-backs on a minor league deal after being granted free agency this offseason.

It was reported yesterday morning by Kiley McDaniel of ESPN that the Diamondbacks had signed minor league free agent catcher Ronaldo Hernandez. The team has still not officially announced this move nor has it shown up on the official websites for the D-backs or Reno Aces. 

C Ronaldo Hernandez has signed a minor league deal with the Arizona Diamondbacks, per source. Deal comes with a spring training invite.

Hernandez played in the Red Sox upper minors for 2021-23 and hit 50 home runs over those three seasons.

— Kiley McDaniel (@kileymcd) December 20, 2023

Mike Hazen has said all off season that he intends to shore up the catching depth behind Gabriel Moreno, and this move would fit as a piece of that puzzle. With only one other catcher on the 40-man roster,  backup José Herrera, the organization is still very thin at the position should anything happen to Moreno.  The D-backs have previously been linked to free agent backup catcher Tucker Barnhart, and this move in no way precludes the team from still pursuing a veteran backup they can put on the roster. 

Now 26 years old, Hernandez was once rated as the Tampa Bay Rays fourth best overall prospect back in 2018.  His ranking slipped in 2019 and prior to the 2021 season Tampa traded him to the Red Sox.  Hernandez grades out as a marginally below average defensive catcher overall, but not without some catch and throw and blocking skills. He improved over the last couple of years going to one knee style catching. While known as a bat first catcher, surely the D-backs will be paying close attention to his catching ability in spring training. 

His best tool on offense is raw power, which grades out at 60.  Indeed he's hit 34 homers in 860 plate appearances since reaching Triple-A, posting a .255/.319/.448 slash line for a .767 OPS.  While that may seem decent enough, it's rated at only 93 wRC+, or about 7% below average. 

The issue is had been his propensity to chase pitches outside the zone limiting his overall output. According to Fangraphs' scouting report he posted a 41% chase rate in 2022. (swinging at pitches out of the zone)  MLB average is 33%.  While the chase rate for 2023 is not available at the moment, that may have improved, as his strikeout to walk ratio of 41/69 was much better than his previous seasons.  His 2023 line was .242/.336/.445 with 17 homers in 393 PA.

His batted ball data shows a sizable increase in ground ball rate over the last two  years coupled with an extremely high popup rate that's persisted throughout his career. He's also seen his pull percentage drop as well.  More balls on the ground, a lot of popups, and less pull means getting to his raw power may be an issue going forward. According to Baseball Savant tracking, all of his Triple-A homers the last few years have been to the pull side. 

Baseball Savant / Baseball Savant

Even with all these caveats, Hernandez still projects to be a significantly better hitter than Herrera.  The average of Steamer projections and  ZiPS forecasts a .243/.297/.400,  .697 batting line.  That would be more than acceptable if the defense is up to par.  Herrera meanwhile has a career batting line of .198/.272/.232, .503 OPS. With a 44 wRC+ his bat is unplayable and despite being at least an average defender, explains why the team is looking to upgrade at backup catcher.

Do D-backs Have Enough Catching Depth Behind Gabriel Moreno?