Luis Castillo was drafted by the Chargers out of Northwestern University in the 1st round (28th overall) of the 2005 NFL draft. He was actually the 2nd pick the Chargers made that year since they had the New York Giants 1st round pick (acquired in the historic Eli Manning-Philip Rivers trade) and used it to select LB Shawne Merriman. The pick of Castillo was a controversial one because of Castillo's positive test result for performance enhancing substances. Before the draft, the tainted defensive line prospect issued a statement to all 32 teams admitting his use of androstenedione. His explanation (or excuse) was that he felt an obligation as team captain to play the 2004 season for his school and his teammates. He took the PED in order to recover from elbow injury that occurred in the first game of the season. Obviously, the Chargers must have believed the explanation to a certain extent and took a high profile risk on the young man.
One of the things Castillo may be best known for as a Charger is the statistical tease he gave everyone in his first two seasons. In his rookie year he started 15 games, made 49 tackles and picked up 3.5 sacks. In his second year, the tackles went down to 37, but his sack total climbed all the way up to 7 despite only starting 9 games and playing in 10. He would never reach those statistical heights again. In 2007 he got to 2.5 sacks (in 10 games), last year he matched that total (in his first season starting all 16 games) and in the other years finished below that.
The other thing Castillo is known for is the fat contract he got before the 2008 season. After what was thought to be just an injury-plagued down year, the Chargers broke out their checkbooks and inked the 3 year veteran to a 6 year, $43.6 million deal. He had a year remaining on his rookie contract, so it was basically a 5 year extension. This raised a few eyebrows at the time, but really seems strange nowadays when Pro Bowl players like Vincent Jackson and Shawne Merriman never received such offers and Marcus McNeill had to wait until the 11th hour to get his.
In November, Superduperboltman wrote a fanpost asking if Castillo was worth the money the Chargers pay him. The answer is somewhat complicated. When compared to the other top paid 3-4 DEs his numbers pale in comparison. However, when the game film was analyzed you could see that he gets a lot of respect from other teams. He gets double teamed almost half the time, which is at least a sign that he's considered as good or better as anyone else in the Chargers defensive front 7 (for whatever that's worth). The film also shows that former Defensive Coordinator Ron Rivera like to use the attention that Castillo gets to scheme ways to have him occupy blockers in order to free up Cooper, Burnett, Phillips or a blitzing DB du jour.
How much is the package that Luis Castillo brings to the table worth to the Chargers? Well, I'll leave that up to you.