Petrasek started his playing career with HV71's youth team in 1993.

He was part of the senior squad in the playoffs of 1995 and won the first Swedish Championship for HV71.

From 2000–01 to 2004–05 Petrasek was contracted by Malmö Redhawks but returned to HV71 for season 2005–06.

In 2008, he won his second Swedish Championship, again with HV71 as an alternate captain for the team.

On July 7, 2010, Petrasek left the Sweden for the first time in his professional career and signed as a free agent to a one-year contract with Belarus team HC Dinamo Minsk of the KHL.