Sekera played at the 2009 World Championship and led the team with a plus-three rating in six games. He was named one of the team’s three best players selected by Slovak coaches. Six of his Olympic teammates also played on this World Championship team that placed 10th.
Sekera captained Slovakia at the 2006 World Junior Championship in Vancouver. He scored two goals and added three assists in six games and his plus-three rating was tied with two players for the team lead.
He played in the Ontario Hockey League (OHL) from 2004-2006 where he was a plus-15 through 51 games in the 2006 season and was named the Max Kaminsky Trophy recipient as the league's Most Outstanding Defenseman.