Astros’ latest coaching hire may be exactly what Yainer Diaz needs for turnaround

In what was a season filled with disappointments for the Houston Astros, one of them that took a bit of a back seat was Yainer Diaz. After his first two full seasons where he posted a .796 OPS and averaged close to 20 homers a season, 2025 was a step back where he put up a .256/.284/.417 line, although the 20 home runs remained steady. However, one consistent criticism of Diaz through the good times and the bad has been the quality of his defense and framing in the field. Now, it seems like the Astros may have a plan to fix that flaw.

Diaz has a pretty strong throwing arm and decent pop times to control the running game, but his blocking metrics have been inconsistent and he has never graded out well when it comes to framing. Given the importance framing has in particular (at least until the ABS challenge system is implemented), it is no wonder that Houston did not keep catching coach Michael Collins during their coaching staff purge earlier this offseason.

Identifying the problem is only the first step, though. The Astros need a plan to execute to get Diaz's catching up to par and their next idea comes in the form of hiring catching coach Tim Cossins who has a solid background in teaching the fundamentals of being a good catcher.

Astros hiring of Tim Cossins gives hope that Yainer Diaz's catching can catch up with his bat

Houston adding Cossins as a catching coach may not seem like much, but a closer look at the details of his background is pretty promising. Once a bullpen catcher, Cossins was a field coordinator and catching instructor with the Marlins and Cubs for a decade before he took a job with the Orioles. While Adley Rutschman's bat and health have been areas of concern, his defensive work behind the plate was extremely consistent under Cossins' tutelage.

Unfortunately, Cossins was a confidant of former Orioles manager Brandon Hyde and when Hyde was fired in the middle of the 2025 season, Cossins got the boot as well in a move that felt like collateral damage. The Orioles' loss is potentially the Astros' gain here especially with how big a bet Houston has placed on Diaz and his future.

At this point, a change of pace in Diaz's instruction feels appropriate. Diaz's aggressive approach at the plate is going to have to be tempered if his bat is going to rebound. However, assuming Cossins is able to get Diaz's defense and framing to appreciably improve, that should give Diaz a much high floor than he currently has.