Piotr Gruszka was member of the national Polish team that won silver medal of World Championship 2006. Gruszka won gold medal of European Championship 2009, where he was Most Valuable Player. On 14 September 2009 he was awarded Knight's Cross of Polonia Restituta. The Order was conferred on the following day by the Prime Minister of Poland, Donald Tusk. He won with Polish team two bronze medals in 2011 at World League and European Championship.