For his career, he played in thirty-six games, making thirty-five starts, scoring ten goals and contributing five assists.

[5] During his college years Duka played two seasons with the Newark Ironbound Express in the USL Premier Development League.

[12] Duka appeared against Colorado Rapids in the 2011 MLS Cup Playoffs as the Crew were eliminated 1–0 by the defending champions in the wildcard round.

[20] He made his debut for the Impact on August 2, 2014, in a 401 Derby match against Toronto FC, coming on as a substitute for Justin Mapp in the 74th minute of a 2–0 defeat.

[22] In the next MLS match for Montreal, away to the New York Red Bulls on August 23, 2014, Duka tallied his first goal for the Impact.

In the 2014–15 CONCACAF Champions League, Duka appeared in all 10 matches the Impact played in their run to the final of the tournament.

[27] In the second leg, at the Olympic Stadium, Duka went the full 90 minutes as the Impact were defeated 4–2 and denied their first-ever CONCACAF title by a 5–3 aggregate score.

[34] At home for the first leg of the semifinals against Columbus Crew SC, Duka came off the bench to replace Oduro in the 61st minute of a 2–1 victory.

[36] At the end of the 2015 season, Montreal expressed interest in bringing Duka back for 2016, with the player saying, "Now, I’m just waiting for the Impact to make an offer.

"[37] However, on January 18, 2016, Duka announced he would not return to Montreal, with the club quoted as saying he wanted to pursue opportunities in Europe.

Duka made his lone appearance with the U-23 national team on February 29, 2012, against Mexico, in the lead up to the 2012 London Olympics.

He was not selected to the US team for the 2012 CONCACAF Men's Olympic Qualifying Championship, where the United States was eliminated in the group stage.