ARIZONA DIAMONDBACKS
D-backs officially ink catcher Jeff Mathis with eye on shoring up pitching staff
Dec 5, 2016, 6:15 PM

Miami Marlins catcher Jeff Mathis (6) prepares to throw out Washington Nationals Max Scherzer (31) during the fifth inning of a baseball game, Thursday, April 21, 2016, in Miami. The Marlins won 5-1. (AP Photo/Alan Diaz)
(AP Photo/Alan Diaz)
Less than two months into a new era, the Arizona Diamondbacks have aggressively tried to tackle their starting pitching problems from 2016.
The trade to acquire Taijuan Walker from the Mariners at the surface stood out statistically in the starting pitcher’s 2.48 batters walked per nine innings. That low rate could help improve an Arizona pitching staff that saw four of its starters rank in MLB’s top-21 of the most frequent walk rates a season ago.
While the front office led by general manager Mike Hazen has already tried to shore up pitching issues via addition, the more recent decision did so by subtraction. The D-backs’ choice not to tender offensive-minded catcher Welington Castillo and sign former Miami Marlins catcher Jeff Mathis — the latter became official Monday — was clearly related to the pitching issues.
“With Jeff, we’re getting a plus defender, game-caller and teammate,” Hazen said in a statement. “His veteran leadership on and off the field will be very valuable in the development of the young core of our club.”
Mathis will be 34 by the beginning of next season and joins a group of catchers led by the raw Oscar Hernandez and versatile Chris Herrmann. At winter meetings, Hazen told reporters Monday that Herrmann could take on a bigger role after hitting .284 with six homers and 28 RBI last year.
Still, it’s Mathis who brings the appeal when it comes to shoring up the issues of the pitching staff.
ESPN’s Mark Simon pointed to Mathis’ pitch-framing abilities — Arizona ranked 28th in MLB in pitch-framing the last two years — to the success of Marlins pitcher Tom Koehler.
In 13 starts with Mathis behind the plate, Koehler looked like a Cy Young contender. His ERA and strikeout-to-walk rate were both 2.65, and opponents hit .191 with a .593 OPS against him. In 20 other starts, Koehler had a 5.66 ERA, and his strikeout-to-walk rate was 1.4; opponents hit .309 against him.
…
From a pitch-framing perspective, there’s this: In Koehler’s career, Mathis has gotten him 12.6 called strikes more than the average catcher would have gotten. All other catchers are at a combined minus-78.3.
Mathis’ career .197 batting average says enough about his offensive abilities, but for a team that invested money into Zack Greinke and talent to acquire Shelby Miller and now Walker, it’s clear that getting better production out of those players and the rest of the pitching staff remains priority No. 1 for Hazen and his staff.
In doing just that, the Diamondbacks think Mathis could be a big help.