Later that year, in April 2009, Rajala competed for Finland at the 2009 IIHF World U18 Championships in the United States. He led the tournament in scoring with 10 goals and 9 assists and broke the previous point record held by Alexander Ovechkin. Rajala was selected as the best forward in the tournament, and was named to the tournament All-Star Team, helping Finland to a bronze medal. Rajala also represented Finland at the 2010 World Junior Championships which were held in Saskatchewan, Canada.