2009-10: In his first OHL season with the Ottawa 67's, Petr Mrazek had a 12-9-1 record in 30 games with a 3.00 goals against average and .905 save percentage. He played in 8 playoff games with a 4-4-0 record, 2.39 goals against average, and .928 save percentage.
2010-11: Had a very solid year with the 67’s, participating in 52 games and posting a 2.84 GAA and .920 save percentage. Struggled in the playoffs, getting swept while putting up a 5.64 GAA and .868 save percentage.
2011-12: Mrazek had an outstanding season – appearing in 50 regular season games for the Ottawa 67's and then handling the bulk of the action as Ottawa reached the OHL semifinals. In international play, he skated for the Czech Republic men's team at the 2012 IIHF World Championship and was arguably the top goalie in the 2012 U20 World Junior Championship. Mrazek was 30-19 with 3 shutouts and had a 2.84 goals against and .917 save percentage in the regular season for Ottawa. In the OHL playoffs he appeared in 17 of 18 games and was 9-8 with a 2.59 goals against and .929 save percentage. He appeared in one game for the Czechs at the World Championship – stopping both shots he faced in nine minutes of action. Mrazek was 3-3 with 1 shutout in six games at the WJC with a 2.49 goals against and .928 save percentage; highlighted by a 52-save effort in a 5-2 win over the USA. Mrazek signed a three-year entry-level contract with Detroit in October 2011.
2012-13: Mrazek made his NHL debut in February 2013 — appearing in two games with the Red Wings — and was in net for Detroit AHL affiliate Grand Rapids during its Calder Cup championship run. He was 1-1 with a 2.02 goals against and .922 save percentage for Detroit. Splitting the goaltending chores for Grand Rapids during the regular season with fellow Red Wings prospect Thomas McCollum, he was 23-16-2 with 1 shutout in 42 games and had a 2.33 goals against and .916 save percentage. The Griffins finished first in the Midwest Division and defeated Syracuse in the finals to capture the Calder Cup. Mrazek played all 24 playoff games and was 15-9 with 4 shutouts; posting a 2.31 goals against and .916 save percentage.
Not the largest goaltender, standing 6’0" and weighing 184 lbs. He possesses a great deal of athleticism and does not give up on shots. Mrazek has been touted as a great competitor, who also has great vision, which makes up for his lack of size.
The debate as to whether Mrazek is NHL-ready will continue to rage on 2013-14, as the Red Wings organization believes that Mrazek is better off gaining experience as the starting goaltender for the AHL's Grand Rapids Griffins than he would be sitting on the bench in Detroit.