Douglas Arguello is a left-handed pitcher from Managua, Nicaragua. The 24-year old was signed as an international free agent in 2001 and has been playing in the Houston farm system since he was 18.
Last season in Salem was the first year he's really broken out and had a great statistical year. He was good with Tri-City in 2006, but hasn't ever had an ERA of under 4 until last season. His strikeout to walk ratio was actually better in 2007 than 2008, but he had an ERA almost a run higher in 2007 with Lexington. His home run rate has remained around 1 per 9 innings for his entire career until last season. Now, before rushing to conclude Arguello made some sort of breakthrough then, it should be noted that Salem is very friendly for hitters and the park just doesn't give up home runs.
That being said, Arguello has been great this season. His PRC is at 11.96, which is the second highest that I've seen this season. He's still walking too many batters, but he's limiting the number of hits and how hard he's being hit by keeping his line drive percentage down (16.9%). The one troubling blip in his stat line is his splits. He's death to lefties, giving up a .192 average when matched up with other southpaws, but right-handed hitters are batting .274 off of him.
His game scores have all been around 50, except for his last two starts. In his last April outing, he didn't make it out of the fourth inning, giving up seven hits and five runs in 3 2/3 innings. He struck out just two and walked five while giving up a home run and hitting a batter. Can't get much worse than that. Five days later, he came out and pitched a complete game, giving up the same number of hits and only one run while striking out six and walking none. His game score for that start was a 75, the highest yet in the minors.
He's given up more line drives in each of his last two starts than he had in his previous three combined. He's also throwing more pitches in games, as his arm has had time to get into a rhythm again after a winter off. Dating back to last season, Arguello has been throwing longer and longer in games, as he was the only Astros minor leaguer to have two complete games last season and was the only member of the Salem staff to throw a shutout. Whether this is a good thing or a bad thing, I'm not sure.
Arguello also doesn't miss a ton of bats. He gets his share of swinging strikeouts, but his K/9 rate of 6.67 is not great for the Texas League. It doesn't appear that he has a great fastball, but I'd bet he has either a slider with good break or a screwball that makes life tough on lefties, much like Randy Johnson or Mike Cuellar had. Obviously, I'm not comparing him to either of those Hall of Fame-caliber guys. Arguello also doesn't induce a ton of ground balls, so I'm leaning towards the possibility of him being more of a left-handed arm out of the bullpen. I'm sure the Astros will keep using him in the rotation for now, but he can definitely be an effective lefty out of a big league bullpen with his numbers from the past few years.