Messages left with union officials were not immediately returned.
The flight, with 53 passengers on board, was delayed about 2 ½ hours while a replacement pilot was arranged, Miller said. It arrived in New York after noon.
The pilot was taken to Fairview Southdale Hospital to have a blood sample taken, then was returned to airport police before being released, Hogan said.
Pilots face drug and alcohol testing when they seek a job, are involved in an accident or return from alcohol rehabilitation. Some are selected for random tests. More than 10,000 pilots are tested each year and about a dozen flunk the alcohol part — a number that has remained mostly steady for more than a decade, according to federal statistics.
Twelve pilots failed the breath test in 2011, 10 in 2010, and 11 in 2009, according to the Federal Aviation Administration.
"Your odds of having an impaired driver on the highway are much higher, but there's a smaller margin for error in aviation," said James Hall, former chairman of the National Transportation Safety Board.
Drinking among pilots got more attention after notorious cases in the 1990s, including one in which a jury convicted all three pilots of a Northwest Airlines flight of flying under the influence. Federal rules were tightened.
Hall said most airlines and other transportation companies now have effective programs to identify and get treatment for employees with drug or alcohol problems. But, he said, an incident like Friday's should lead to a re-examination of protocols, including the 0.04 standard to testing procedures.