"The A's kicked off their latest roster makeover Friday by trading pitchers Trevor Cahill and Craig Breslow to the Arizona Diamondbacks.

Oakland received pitchers Jarrod Parker and Ryan Cook and outfielder Collin Cowgill, three prospects who could play significant roles for the A's in 2012.

Cahill's name surfaced Wednesday as a trade possibility. Until then, it was fellow starter Gio Gonzalez and closer Andrew Bailey who were most heavily rumored to be leaving Oakland. Both remain strong candidates to be dealt, with Texas interested in Gonzalez.

"It's never easy to trade a guy who was a focal point of your team for three years," A's assistant general manager David Forst said of Cahill. "But we understand every so often you need to shuffle the deck."

Cahill broke into the A's rotation in 2009, a 21-year-old who appeared part of the foundation upon which the team would build. He went 18-8 with a 2.97 ERA in 2010 and was an All-Star. Last April, he signed a five-year, $30.5 million contract extension with club options for 2016 and 2017.

That affordable, long-term contract was attractive to the defending National League West-champion Diamondbacks, who will add Cahill to a rotation that includes Daniel Hudson, Josh Collmenter and Ian Kennedy.

"We think we've got four young starters who are as good as anybody in the N.L. West," Arizona G.M. Kevin Towers said."