MLB Rookie Report: Dayan Diaz, RHP, Cincinnati Reds

Here's another weekend roster move for the Cincinnati Reds: the promotion of right-handed relief pitcher Dayan Diaz from Triple-A Louisville to the major leagues. Who is this guy? Let's find out.

Dayan Diaz is from Colombia and was originally signed by the Houston Astros back in 2005. He spent three years in the Venezuelan Summer League and didn't really emerge as a prospect until 2012, when he posted a 1.85 ERA with a 64/30 K/BB in 58 innings, collecting 19 saves in 22 attempts. This attracted the attention of the Chicago Cubs, who signed him as a minor league free agent for 2013.

Injuries limited him to just 21 innings in '13. He moved on to the Boston Red Sox system where he posted a 1.80 ERA with a 56/21 K/BB in 50 innings between High-A and Double-A, then a 1.89 ERA with a 49/28 K/BB in 57 innings in Triple-A in 2015. The Reds signed him for '16 and he continued to perform well in Triple-A, posting a 1.88 ERA with a 7/4 K/BB in 14 innings.

Diaz is small for a right-hander at 5-10, 195, but the 27-year-old has a quick arm with a fastball up to 95 MPH. Lack of a change-up has relegated him to relief work but he has a decent slider and can be tough on right-handers when his command is on. This is a typical 10th man/middle relief profile but he represents a solid pick-up for the Reds on the minor league free agent market.

Here's a whiff on a breaking ball from late last season.