The White Sox finally confirmed the trade after 24 hours of speculation following a New York Daily News report.
According to baseball sources, the hang-up in the trade was the difference in salary of Teahen -- who can make as much a $5 million in arbitration in 2010 -- and the salaries of Getz and Field, who combined will make about $900,000.
Eventually the teams were able to come to an agreement, as cash considerations were sent to the White Sox to make up for the discrepancy.
White Sox general manager Ken Williams said Teahen would be the White Sox's starting third baseman and last year's rookie star, Gordon Beckham, would be switched from third to second.
That was good news for Teahen, who called third "my comfort position."
"I can handle the outfield and play there, but third base is my No. 1 position," he said.
Teahen, 28, hit .271 with 12 home runs and 50 RBIs in 2009. He primarily was a third baseman for the Royals but also played first base, second base and right field. He may replace right fielder Jermaine Dye after the White Sox chose to buy out Dye's final year of his contract on Friday. But the versatile Teahen also could play second or third in Chicago.
Getz, 26, hit .261 with two home runs and 31 RBIs in 107 games for the White Sox last season.
Fields hit .222 with seven home runs and 30 RBIs in 79 games for the White Sox. He was optioned to Triple-A Charlotte on July 29 and recalled on Sept. 1.
Information from the Associated Press contributed to this report.