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The Cincinnati Reds signed right handed pitcher Dayan Diaz as a minor league free agent after the 2015 season and gave him an invite to big league spring training. The 26-year-old spent his 2015 season with the Double-A and Triple-A affiliates of the Boston Red Sox.

Boston sent the 26-year-old Diaz to their Double-A affiliate in Portland (Maine) to work out of their bullpen to start the season. He would make two appearances in the first week of the season, picking up a save in 2.1 perfect innings of relief. In the second week of the season he made two more appearances, allowing a run in 3.0 innings with three strikeouts. He wrapped up the final week of April with two more appearances, both 2.0 innings of shutout work. He would post a 0.96 ERA in 9.1 innings with just one walk and eight strikeouts while holding opposing batters to a .152 average.

May began much like April ended. He tossed 4.1 shutout innings, allowing just one hit and striking out five batters in the first week. In what turned out to be his final appearance at the Double-A level he allowed a run in 2.0 innings with a walk and four strikeouts. It would be three more days before he’d make his Triple-A debut for Pawtucket, throwing 2.1 shutout innings on the 12h. He would make two appearances in the next week, both longer outings as he combined for 5.2 innings of 1-run baseball with six strikeouts. In the last week of May he allowed a run in 3.0 innings to finish May with a 1.56 ERA in 17.1 innings. Diaz would allow just three walks and strike out 19 batters.

June got out to a very rough start. In his first two appearances, both lasting 2.1 innings, he allowed six earned runs. He would make just one appearance over the next 11 days, tossing a shutout inning on the 13th before returning to the mound on the 20th. From June 20th through the end of the month he would make three more appearances, tossing 5.0 shutout innings with a walk and three strikeouts. In somewhat limited action he would post a 4.26 ERA in 12.2 innings with five walks and 12 strikeouts.

The four game scoreless streak continued into July as he tossed 4.1 shutout frames in the first week for Pawtucket over two games. Another two appearances and 4.0 shutout frames followed the next week. The third week saw his workload increase as he tossed 6.0 innings spread out of two games without an earned run, but he did have four walks. On the 25th he turned in his 11th consecutive appearance without an earned run, but the streak came to an end in his final showing of the month, allowing a run on three walks in 0.1 innings. His ERA in July was a shiny 0.54 over 16.2 innings, but he walked 12 batters with 15 strikeouts as his WHIP ballooned to 1.38 due to the high rate of free passes.

On August 2nd he returned to the mound and made his longest appearance of the year, tossing 4.0 shutout innings, but walking two batters without a strikeout. In the next game he allowed two runs on two hits and two walks in 2.0 innings as his control issues continued. The right hander only made one appearance in the second week of the month, tossing 2.2 shutout frames with two more walks and four strikeouts. It was his 4th consecutive multi-walk game and his 7th among his last nine appearances. He would make two trips to the mound in the third week of August, allowing one earned run in 4.0 combined innings, walking a batter in each game. He would take the mound for the final time in August on the 22nd, tossing a shutout frame with two strikeouts. In the final week of the season, the first week of September, he would toss 3.0 shutout innings with a walk and a strikeout over three games. In the last five weeks of the year he posted a nice 1.62 ERA, but again struggled with his walk total, handing out nine free passes in 16.2 innings with 12 strikeouts.

After the regular season was over he began playing in the Venezuelan Winter League where he made 18 appearances with a 2.20 ERA. In his 16.1 innings pitched he allowed five walks and had 13 strikeouts.

On the season he held batters to a .202 average and a sub .600 OPS. He also saw his walk rate climb as the year went along and had struggles against left handers, who walked 21 times with 35 strikeouts against him in 125 plate appearances (righties had just nine walks and 31 strikeouts in 178 plate appearances). He kept his ERA strong throughout the season, but did seem to struggle some more as the season progressed. It’s hard to complain much about a 1.73 ERA in 72.2 innings with 30 walks and 66 strikeouts though.

AA 1.15 15.2 7 0 2 17 0.57
AAA 1.89 57.0 47 3 28 49 1.31

Dayan Diaz Scouting Report


Fastball | Diaz has a live arm with a fastball that works in the 92-96 MPH range at times, but will also sit 91-93 at times. The pitch has some armside run to it.

Slider | The pitch works in the low 80’s and is an average offering with 12-6 biting action to it.

His velocity slips in his longer outings. He doesn’t repeat his mechanics all of the time, which likely relates to his struggles with control as the season went along. His struggles in 2014 and 2015 against lefties could be an issue moving forward, but he’s performed very well against righties. He profiles as a possible 6th/7th inning type of reliever, but he will need to figure out his control more than he showed down the stretch in 2015.