Cahill, who is 19 years old, was Oakland's first selection in the 2006 draft. He started four games last year for the A's Arizona League affiliate, striking out 11 batters in nine innings of work while allowing three earned runs.
Rodriguez also spent his 2006 season with the Arizona A's, going 5-2 with a 7.42 ERA in 15 games. In 43.2 innings, Rodriguez struck out 59 batters. The 20-year old combined with Cahill to throw a no-hitter against the Arizona Cubs on August 30 last year.
In eight games with the Cougars in 2007, Piekarz was 1-3 with a 6.75 ERA in 17.1 innings pitched. As a Cougar in 2006, Piekarz led the A's farm system with a 3.26 ERA while alternating between a starting and relief role. Madej, pitching exclusively from the Cougars bullpen this season, was 0-2 with a 4.50 ERA in 10 appearances.
The Kane County Cougars' media department contributed to this report.