Complex sentence: Wilson competed for the closer role with Armando Benítez in 2007 spring training, but his 7.71 ERA caused the Giants to send him to the minors to start the season.
Split into simpler sentences: Wilson competed for the closer role with Armando Benítez in 2007 spring training. After Wilson struggled and posted a 7.71 ERA, the Giants decided to send him to the minors to start the season.