Career
Martínek was an eighth-round selection, 228th overall, by the New York Islanders in the 1999 National Hockey League Entry Draft. After playing professionally for five seasons in his native Czechoslovakian Extraliga with The Human Context České Budějovice, he joined the Islanders in 2001 and entrenched himself as a mainstay on the blueline. With the exception of Rick DiPietro, Martínek had the longest tenure with the Islanders of any current player until he was signed as a free agent by the Columbus Blue Jackets on July 6, 2011.
Martínek opened the 2011-2012 season with the Blue Jackets, scoring one goal in seven games before he suffered a season-ending concussion against the Detroit Red Wings on October 21, 2011.
In returning to health and as a free agent with the National Hockey League lockout in effect, Martínek signed as he did during the previous lockout with his Czechoslovakian team, České Budějovice, on September 19, 2012. He appeared in only four games with the club before he left to return to North America.
With an agreement in place to end the labour dispute, Martínek was signed to a one-year deal with his former team, the New York Islanders, to add depth and compete for the final defensive spot on January 13, 2013.