He was selected by the Seattle Mariners in the 2004 Major League Baseball draft but didn't sign, instead opting to go to Bellevue Community College and later the University of Washington.

He was later selected by the Boston Red Sox with their first pick, 55th overall, in the 2007 Major League Baseball draft.

Hagadone originally planned to attend Bellevue Community College but later received a scholarship to the University of Washington in Seattle.

During his time as a Husky, he was the primary closer and teammates with future Cy Young Award winner Tim Lincecum.

[3]Hagadone reported to the Lowell Spinners of the Class A Short-Season New York–Penn League after signing his first professional contract with the Boston Red Sox on July 1, 2007.

He was roughed up in his pro debut, allowing five runs on six hits and a walk while fanning one over one and one third innings against the Aberdeen IronBirds on July 18.

[4]He held opposing hitters to a .103 average and just one extra-base hit, a double, during his scoreless streak for the rest of 2007.

He gave up two unearned runs in his first inning of the season on April 5 against the Kannapolis Intimidators, snapping a personal 23-inning scoreless streak.

[8] In a loss versus the Tampa Bay Rays on July 6, 2012, Hagadone fractured his left forearm in a fit of frustration.

As that date was also the non-tender deadline that year, and the Indians did not tender him a contract, Hagadone subsequently became a free agent.