03 May 2010
| Cesar Valdez
On Monday, the Diamondbacks called up SP Cesar Valdez to make his major league debut against the Houston Astros. Kevin Mulvey was sent back to AAA to open a roster spot. Valdez had made 4 starts for AAA Reno, going 1-1 with a 3.80 ERA, with a nice 25K/5BB ratio over 23.2 IP. Here is a closer look at his four minor league starts:
It is clear that to be successful, Valdez must keep the ball on the ground. In his only poor start, on April 14 against Salt Lake City, he had more fly ball outs than ground ball outs, and also allowed 2 Home Runs. Although Valdez has struck out over one batter per inning this year, his career rate is only 7.1K/9, and in 2009 his strikeout rate had slipped down to only 5.6K/9 for AAA Reno. Valdez has also reduced his walk rate significantly in 2010, walking only 1.9BB/9 this year after allowing almost 3 BB/9 over the last two seasons. Despite the good strikeout numbers this year, Valdez doesn't have great stuff, and needs to control the walks and get ground balls to be successful. Another point to note is that left-handed batters are hitting 10-29 (.345) against Valdez this year, while he has held right-handers to 13-69 (.217).
Reynaldo Navarro - Carlos Rosa Trade
Last Friday, the Diamondbacks sent Visalia SS Reynaldo Navarro (20) to the Royals for AAA pitcher Carlos Rosa (25). Not only is the Diamondbacks major league bullpen a disaster so far this year, but the injuries to Kris Benson and Leo Rosales have left the organization without much depth at the AAA level. Rosa has made 9 appearances in the majors over the last two years, compiling a 3.21 ERA over 14 IP. Rosa had been a starter in the Royals system through the 2008 season, but the Royals decided to switch him to relief in 2009. The switch occurred because Rosa was having trouble with his secondary pitches. He has a solid fastball around 93 mph with good movement, but his only other pitch is a slider in the low-to-mid 80s. He's had little success with his changeup or curveball. The switch to the bullpen helped his strikeout rate, as he struck out 80 in 71 IP last year, but he also struggled with walks, allowing 32 (4.1 BB/9 IP). There are reports that Rosa still has not adapted well to the bullpen - that he struggles to get ready on short notice and is not able to pitch on consecutive days. For now, Rosa will add depth to the AAA bullpen. He doesn't have the repertoire to be a closer or set-up man yet, but he could eventually see some middle relief work in Arizona.
Reynaldo Navarro signed with the Diamondbacks in 2007 at the age of 17, and was in his 4th season in the Minors. Defensively, Navarro has good range and a solid arm, but his offense is still a question. He has a career OPS of only .645 in the minors, including a .636 OPS in the hitter friendly California League this season. The Diamondbacks have a similar good-field, no-hit shortstop in Pedro Ciriaco, and 2009 draft pick Chris Owings may be ready to move up to Visalia from Low-A South Bend, where he has an .831 OPS after 22 games.