He was promoted to their senior squad in the 2006–07 season and played a total of 30 matches in the Slovenian first division, scoring 11 goals in the process.

[5] On 26 September 2007 he scored four goals in KNVB Cup in a match against IJsselmeervogels,[6] but later moved to Emmen on loan and remained there until January 2009.

[8] On 2 February 2011, Groningen sporting director Hans Nijland said that Matavž had already agreed terms with Napoli and that he was looking forward to joining them.

[13] On 9 October 2010, Matavž scored a hat-trick for Slovenia in the UEFA Euro 2012 qualifying match against Faroe Islands.

[21] In April 2024, several Slovenian media outlets reported that Matavž had been charged with domestic violence, and that the court allegedly imposed a restraining order, preventing him from contacting his wife and children.