[1] On March 11, 2004, Zawadzki became the first person to get a hit at Petco Park when he doubled off the wall as a freshman for San Diego State against Houston.

[2][3] During the 2005 summer, Zawadzki played for the Wareham Gatemen in the Cape Cod Baseball League in Massachusetts alongside teammates Daniel Bard and Justin Masterson.

In 2009, he split the season between the Advanced A Lake Elsinore Storm and the AA San Antonio Missions and hit .285 combined in 128 games.

In November, 2011, Zawadzki signed a minor league contract with the Los Angeles Dodgers and was assigned to the Triple-A Albuquerque Isotopes to start the season.

Zawadzki signed a minor league contract with the St. Louis Cardinals on August 10, 2012, and was assigned to the Triple-A Memphis Redbirds.

On December 18, 2012, the Toronto Blue Jays announced that Zawadzki had been signed to a minor league contract with an invitation to spring training.

In 2018, Zawadzki was named a coach for the Lowell Spinners, the Class A Short Season minor league affiliate of the Boston Red Sox.