As he only managed to score 11 goals in his first three-and-a-half years as a senior, Augustinussen was stamped by a media pundit as being "not the fastest moped on the dockside" ("ikke den hurtigste knallert på havnen") in August 2003,[1][2] and did not look like cutting it at the highest sporting level of Danish football.

However, Augustinussen was moved back to the centre midfield by new AaB coach Erik Hamren, where he established himself as a consistent part of the starting line-up.

[2] He suffered a knee injury in October 2006, but returned to the AaB side in August 2007, and helped the team win the 2007–08 Superliga championship.

In June 2008, he made his debut for the senior Denmark national football team in a friendly match 1–1 draw with Poland, coming on as a substitute to replace Christian Poulsen in the 77th minute.

He played his second national team game in June 2009, replacing Christian Poulsen in the 71st minute of 1–0 win against Sweden in the 2010 FIFA World Cup qualification tournament.