The Seattle Mariners and starting pitcher Luis Castillo have agreed to a five-year, $108 million contract extension, which includes a sixth year vesting option. After the Mariners sent four prospects to the Cincinnati Reds in exchange for Castillo, they obviously wanted to lock him up. With this contract they do just that, making him a key part of their rotation for the next half decade. The 29-year-old has continued his stellar season since the trade, posting a 3-2 record, 2.83 ERA, 1.09 WHIP, and 64:13 K:BB ratio over 54 innings pitched. Because of park factors and team context, this extension should keep Castillo's value higher than if he were to stay with the Reds heading into next season.