According to multiple baseball sources, the Red Sox will hire Curt Young as their next pitching coach, with a formal announcement coming as soon as today. Young will replace John Farrell, who left the Red Sox last week to become the manager of the Toronto Blue Jays.

Young spent the last seven seasons as the pitching coach of the Athletics. During that time, the A’s have a 4.03 ERA that ranks as the best in the American League. The Oakland staff also had a 3.58 this year that led the American League.

“We are lucky to be able to add an experienced pitching coach the caliber of Curt Young to the organization,” GM Theo Epstein said in a press release announcing the hiring. “Curt has a proven track record of success in this job, mixing excellent relationship-building skills with expert knowledge of pitching and how to get hitters out at the Major League level. Pitchers who have worked with Curt swear by him, and the results speak for themselves. We think he will work well with our pitching staff and within the culture of our clubhouse.”

Young announced just over a week ago that he would decline Oakland’s offer of a contract for 2011 in order to pursue other opportunities in the major leagues. He interviewed with the Sox last Monday, and immediately became a leading candidate for the position.

The Sox also considered other external candidates and interviewed a pair of internal candidates, Mike Cather (an advance scout in 2010 who had previously spent four years as a minor league pitching coach) and minor league pitching coordinator Ralph Treuel.

But, in the end, the Sox will turn to the man who has helped turn the Athletics into a factory for talented young pitchers, with a young staff that includes top talents such as Trever Cahill and Brett Anderson.

Rob Bradford contributed to this report.