A's trade pitcher Jeff Samardzija to White Sox

The Oakland Athletics traded an All-Star for the third time in less than two weeks, sending right-hander Jeff Samardzija to the Chicago White Sox on Tuesday.

Right-hander Michael Ynoa also was dealt to Chicago. Oakland obtained right-hander Chris Bassitt, catcher Josh Phegley and infielders Rangel Ravelo and Marcus Semien.

An All-America wide receiver at Notre Dame, Samardzija was 31-42 with a 3.97 ERA for the Chicago Cubs from 2008 until July 5, when he was traded to the A's. He went 5-6 with a 3.14 ERA for Oakland.

Samardzija, who turns 30 on Jan. 23, made $5,345,000 this year and is eligible for salary arbitration. He can become a free agent after the 2015 season.

''We're going to make every effort to make this a long-term relationship,'' White Sox general manager Rick Hahn said. ''We felt that this was a premium starter who fit, not just in terms of how he fit in our rotation, but how he fit in our clubhouse.''

The White Sox have been a prominent team in the offseason. On Monday at the winter meetings, Chicago agreed to a $46 million, four-year contract with closer David Robertson, a person familiar with the deal said. The person spoke on condition of anonymity to The Associated Press because the agreement had not been announced.

Recently, Chicago agreed to a $25 million, two-year contract with first baseman Adam LaRoche and a $15 million, three-year deal with left-hander Zach Duke.

''We've moved the chains to improve this club in what we feel is dramatic fashion, but we still have work to do,'' Hahn said. ''It's starting to get a little tight. We spent a pretty good chunk of what we had available to us, but at the same time it just means it's time to get a little more creative.''

While Chicago is adding after finishing fourth in the AL Central at 73-89, Oakland is subtracting.

Following its loss to Kansas City in the AL wild-card game, Oakland traded third baseman Josh Donaldson to Toronto on Nov. 28 and first baseman/outfielder Brandon Moss to Cleveland on Monday.

Oakland was 22nd in payroll at the end of the regular season at $92 million. Moss had a $4.1 million base salary this year and is eligible for arbitration. Donaldson is eligible for arbitration for the first time after Oakland renewed his salary this year at the $500,000 major league minimum.