Born: November 17, 1990
Height: 6′ 1″
Weight: 175
Bats: Right
Throws: Right
Signed: Int. FA, Pittsburgh Pirates, 2008
How Acquired: Int. FA
Country: Venezuela
Agent: Magnus Sports

(Photo Credit: David Hague)


Diaz has developed into one of the top catching prospects in the minors.  He’s always been strongly defensively, with good agility behind the plate and a strong arm.  He struggled to hit in the low minors, including a two-year stint in low A, but once he reached high A his offensive game started coming around.  He had a breakout season in AA in 2014.  Diaz hasn’t shown a lot of power, but he makes good contact and shows good strike zone judgment.  He’s had some fairly large platoon splits.

VSL:  272/372/409, 232 AB, 13 2B, 2 3B, 5 HR, 29 BB, 47 K, 3-7 SB

Diaz was the primary catcher on the Pirates’ VSL affiliate, which dominated the league.  He hit well considering it was his first season, with solid BB and K numbers.  He threw out 45% of opposing base stealers, while also playing a little at first.

R:  218/280/310, 142 AB, 5 2B, 1 3B, 2 HR, 10 BB, 28 K, 0-2 SB

Diaz was the primary catcher in the GCL, getting about twice as much playing time as Joey Schoenfeld even though Schoenfeld hit much better.  Diaz struggled at bat, with weak plate discipline.  His defense was much better, as he threw out 41% of opposing base stealers.  The Pirates made it clear that they liked Diaz more than Schoenfeld (who has since been released) and that they think he’ll eventually hit.

A:  221/279/328, 326 AB, 23 2B, 3 3B, 2 HR, 23 BB, 69 K, 6-7 SB

The Pirates jumped Diaz up to West Virginia, where he was the regular catcher.  He continued to struggle at the plate, with strike zone judgment that was marginal at best.  He hit LHPs decently (257/337/378), but couldn’t hit RHPs at all (210/261/313).  His best month was August, when he hit 269/310/433, which he followed by going 4-for-10 in September.  His CS% dropped to 22% and he had a lot of errors, 16 in 82 games.  He’s an aggressive catcher and doesn’t hesitate to try to catch runners off base, so that may have led to some of the errors.

A:  208/262/288, 313 AB, 14 2B, 1 3B, 3 HR, 22 BB, 51 K, 2-4 SB

Diaz returned to West Virginia and struggled even more at the plate.  He got off to a nightmarish start, hitting .138 in the first two months.  Almost all his production, including all his HRs, came in July, when he hit 306/307/514.  He threw out 27%.

A+:  279/382/399, 183 AB, 12 2B, 2 3B, 2 HR, 31 BB, 33 K, 4-8 SB

Diaz shared the catching position at Bradenton with Jacob Stallings, although Stallings got a larger amount of playing time.  Diaz had easily his best season at the plate since his initial VSL season.  He threw out 26% of base stealers, compared to Stallings’ 21%, although he had some trouble with passed balls, committing ten in 55 games behind the plate.

AA:  328/378/445, 326 AB, 20 2B, 6 HR, 30 BB, 51 K, 3-5 SB
AAA:  152/243/182, 33 AB, 1 2B, 3 BB, 6 K, 0-1 SB

Diaz had a breakout season as the regular catcher at Altoona, building on his 2013 progress with the bat.  He still didn’t hit for a great deal of power, but he’s strong enough that he could develop more eventually.  He had a decent walk rate and didn’t strike out much.  Diaz had a huge platoon split, batting 413/450/578 against LHPs and 268/330/352.  Platoon splits with right-handed hitters, though, tend to level off over time.  Diaz threw out 33% of base stealers in AA and drew good reviews for his receiving.  The Pirates moved him up to AAA for the last two weeks of the season.

AAA:  271/330/382, 325 AB, 16 2B, 4 3B, 4 HR, 29 BB, 47 K, 1-5 SB
MLB:  000/000/000, 2 AB, 1 K

The Pirates rebuffed numerous inquiries about him at the trade deadline and then, as expected, added him to the 40-man roster in November.  He spent 2015 at Indianapolis, where he shared catching duties with Tony Sanchez.  He didn’t hit as well as the previous two years, largely due to a rough start, as he had a .559 OPS in April.  He wasn’t overmatched, making good contact with a decent walk rate.  He had trouble with RHPs, posting only a .661 OPS against them.  His OPS against LHPs was .817.  Diaz threw out 30% of base stealers and his defense generally continued to get excellent reviews.  In fact, Baseball America named him the best defensive catcher in the minors.  The Pirates called him up for September, but he got just two ABs and, strangely, no time behind the plate, as Clint Hurdle seemed to regard him solely as an emergency catcher.

A+:  391/464/522, 23 AB, 1 HR, 4 BB, 2 K, 0-1 SB
AA:  286/375/286, 7 AB, 1 BB, 1 K
AAA:  266/289/298, 94 AB, 3 2B, 3 BB, 17 K, 1-1 SB
MLB:  000/000/000, 4 AB, 1 K

The Pirates went with Francisco Cervelli and Chris Stewart at catcher, so Diaz was return to AAA.  He started off on the disabled list, though, due to a sore elbow.  In the end, he had to have surgery to clean it out.  The injury was costly, because both Cervelli and Stewart got hurt.  Instead of Diaz getting a significant look in the majors, the Pirates had to give a lot of playing time to Erik Kratz and Eric Fryer.  Diaz returned in July and worked his way through a rehab program.  He played one game in the majors, when the Pirates were shuffling catchers around, but they sent him to AAA after that so he could play regularly and so they could hang onto Fryer for some reason.  Diaz apparently had no ill effects from the elbow surgery, as he threw out eight of the 13 runners who tried to steal on him in AAA, as well as two of two in AA and the only one in the majors.

AAA:  266/298/339, 218 AB, 10 2B, 2 HR, 9 BB, 36 K, 3-3 SB
MLB:  223/265/314, 188 AB, 14 2B, 1 HR, 11 BB, 38 K, 1-1 SB

Diaz divided his time between Pittsburgh and Indianapolis.  With Francisco Cervelli frequently out with injuries, he got several callups and, in September, played most of the time.  Diaz’ hitting in AAA went downhill quite a bit from what it had been in 2015 and he struggled in the majors.  He also had trouble behind the plate, as pitch framing data showed him to be well below average.  He did show a strong arm, possibly helped by a healthy elbow; he threw out 46% of base stealers in AAA and 30% with the Pirates.

MLB:  286/339/452, 252 AB, 12 2B, 10 HR, 21 BB, 40 K, 0-1 SB

Diaz spent the season as Cervelli’s backup, although he got a lot of playing time due to Cervelli’s concussion issues.  The two of them combined to give the Pirates more production from the catcher position than any other team.  Diaz hit better than at any time in his career, with unprecedented (for him) power.  He was very consistent, with one bad month (May, with a .483 OPS) and no other month with an OPS below .748.  Diaz hammered LHPs, with a .925 OPS, although it came in only 84 plate appearances.  He had a .730 OPS against RHPs.  He threw out 28% of base stealers, which was exactly league average.  (The Pirates got very few innings from LHPs, so their catchers probably got less help than the norm from their pitchers.)  The team did have issues with wild pitches, a category in which they led the majors, and both catchers appear to have contributed about equally.  Oddly, Diaz had no passed balls, but he had a lot of errors (9).  Pitch framing data considered him below average.

A+:  400/571/800, 5 AB, 2 2B, 2 BB, 1 K, 1-1 SB
AAA:  414/433/517, 29 AB, 3 2B, 1 BB, 5 K
MLB:  241/296/307, 303 AB, 14 2B, 2 HR, 23 BB, 56 K

Diaz missed all of spring training with an undisclosed viral infection.  He rejoined the Pirates in late April and, with Cervelli continuing to struggle with concussions, ended up as the starting catcher.  He struggled through a dismal season.  His hitting fell off sharply, with the power almost completely disappearing.  His receiving also fell off and he finished at the bottom among catchers who got significant playing time in pitch framing.  He threw out about the same percentage, at 26%, but committed eight passed balls and a dozen errors.  Late in the season, he lost the starting job to Jacob Stallings.  He missed the last week and a half of the season with a knee injury that didn’t require surgery.

It’s conceivable that Diaz’ illness contributed to his sharp decline in 2019, although it’s impossible to say without knowing what it was.  Stallings was clearly better on both offense and defense, and the Pirates seem to have acknowledged that they need catching help, although it’s a given that they won’t spend any money to acquire it.  If they do find somebody, Diaz’ job will be in jeopardy, as he has no options left.

2019: $578,500
Signing Bonus: $20,000
MiLB Debut: 2009
MLB Debut: 9/12/2015
MiLB FA Eligible: N/A
MLB FA Eligible: 2020
Rule 5 Eligible: N/A
Added to 40-Man: 11/20/2014
Options Remaining: 0 (USED:  2015, 2016, 2017)
MLB Service Time: 3.088
November 7, 2008: Signed by the Pittsburgh Pirates as an international free agent.
November 20, 2014: Contract purchased by the Pittsburgh Pirates.