He competed for the Croatia national team at the 2012 Summer Olympics in London, winning the bronze medal.

At a young age he started playing handball in his hometown club of HRK Krilnik.

On 9 November Gojun showed great playing skill in defense against RK Zagreb in a defeat of 27:24.

[4] On 25 December Franko Mileta was sacked and Williams Černeka took over the team for the rest of the season.

Gojun and his team began a strong campaign finishing third in the first half of the season granting them the championship play-offs.

The next season Zamet was placed 8 in the league and reached the quarter-final of the Cup where they lost to RK Nexe Našice.

In June 2008 Gojun moved to RK Siscia from Sisak where he was called up by head coach Slavko Goluža.

Gojun established himself as more of an attacking player from the start scoring averagely four or five goals per match.

[11] On 12 March 2009 Gojun scored 8 goals against RK Moslavina Kutina with the result ending in 31:22 for Siscia.

[13] On 11 July 2009 it was announced that Gojun would be joining the Croatian power house RK Croatia Osiguranje Zagreb.

[14] Gojun made his first appeared for the club at friendly tournament in August called Poreč handball cup.

Gojun made his EHF Champions League debut on 3 October 2009 against Norwegian club Fyllingen Håndball in an away match where Zagreb won 22:29.

Gojun's first appearance for the club was on the 27 of August 2012 at the IHF Super Globe where Atlético won their first match 28:23 against El Jaish.

[26] Atlético started a good domestic campaign with Gojun providing a big role in attack and defense.

[28] On 21 October Atlético defeated CB Cangas 34:13, Gojun didn't score but he did provide a spectacular defensive wall.

[30] In a Copa ASOBAL match against Naturhouse La Rioja Gojun scored three goals in a win for Atlético of 30:34.

On 4 May Atlético won the final of the Copa del Rey 28:38 against Naturhouse La Rioja.

[42] In a surprise victory RK Gorenje Velenje defeated PSG 30:28 in the EHF Champions League.

[44] In September PSG secured the Trophée des champions yet again, Gojun even scored one goal in the match.

[46] In November PSG got knocked out of the Coupe de la Ligue in the quarter-finals by Nantes.

[47] PSG once again reached the quarter-finals of the EHF Champions League but lost to Veszprém just like the previous year.

[51] After playing for various youth squads he was invited to the senior national team in November 2007 by head coach Lino Červar to participate in their preparation in Poreč.

[57] At the 2011 World Championship Croatia passed the group stage and were knocked out during the main round by Sweden.