Career
Amateur
Frolík played two seasons in the Czechoslovakian Extraliga for Rabat Kladno before being selected tenth overall in the 2006 National Hockey League Entry Draft by the Florida Panthers. While playing in Kladno, Frolík was nicknamed "The Baby Jágr" due to his similar playing style and appearance to Jaromír Jágr, who also played for Kladno earlier in his career. To add to his overwhelming resemblance, Frolík, who cites Jágr as his role model, wore #68 at the Panthers" rookie camp.
Beginning in the 2006-2007 season, Frolík began his North American career playing at the junior ice hockey#Major junior level for the Rimouski Océanic of the Quebec Major Junior Hockey League (QMJHL).
Professional
Frolík made his National Hockey League debut for Florida during the 2008-2009 season, in which he finished with 21 goals and 24 assists for 45 points in 79 games played. During his third season with the Panthers, in 2010-2011, he was traded to the Chicago Blackhawks, along with goaltender Alexander Salák, in exchange for Jack Skille, Hugh Jessiman and David Pacan on February 9, 2011.
Frolík scored his first goal as a Blackhawk on March 2, 2011, against the Calgary Flames. On July 15, 2011, Frolík signed a three-year contract extension with the Blackhawks at an annual average value at $2.333 million.
During the 2012-2013 National Hockey League lockout, Frolík played for Piráti Chomutov in his native Czechoslovakian Republic.
On May 27, 2013, during the 2013 playoffs, he scored the second post-season penalty shot goal of his career against Jimmy Howard of the Detroit Red Wings, becoming the first player in National Hockey League history to score more than one career penalty shot goal in the post-season. In the subsequent off-season, on June 30, 2013, Frolík was traded to the Winnipeg Jets in exchange for a thirdand fourth-round pick at the 2013 National Hockey League Entry Draft. On July 29, 2014, Frolík and the Jets agreed on a one-year, $3.3 million contract.
He finished with 19 goals and 23 assists on in the regular season, but was held pointless during the Jets" four-game sweep at the hands of the Anaheim Ducks in the 2015 playoffs.
On July 1, 2015, Frolík, as an unrestricted free agent, signed a five-year, $21 million contract with the Calgary Flames at an annual average value of $4.3 million.