Jetta is a small, but extremely quick and skilful player who was overlooked in both the 2007 and 2008 drafts, before having a breakthrough year for Swan Districts in 2009. He represented Western Australia in their state game against South Australia in June 2009 and kicked three goals, including the WA's last goal in the final minutes. He is the cousin of Neville Jetta who plays for Melbourne and his brother Graham Jetta plays for Swan Districts.
Jetta was impressive on his AFL debut against Carlton in the opening round of the 2010 NAB Cup, and created nationwide interest in his debut season as he scored 19 consecutive behinds before finally kicking his first AFL goal. In Round 19, 2010, against Hawthorn, he appeared to have broken his drought with a goal on the three-quarter-time siren, only to have the kick ruled out when it was judged to have been made a split-second after the siren. But in the 4th quarter, Jetta finally kicked a goal in the final five minutes, to a standing ovation from the Sydney Cricket Ground (SCG) crowd.
2011 was a relatively disappointing year from Jetta as he struggled to have an impact in several games. While he was able to have an influence at times throughout the year when he came on as the Swans' substitute, he often found it difficult to find the ball through 4 quarters of football. Although he suffered a disappointing 2011 season, he had an impressive lift of form in the 2012 season. The most notable improvements in his form are improved foot speed, kicking accuracy and decision making. In 2011, Jetta only managed to kick 9 goals in the entirety of the season, yet by the end of round 16 of the 2012 season he had kicked 36, making him first for goals in the Sydney squad and seventh in the competition itself. Jetta has improved immensely and has credited this to an outstanding pre-season.
On June 8, 2013, Jetta re-signed with the Sydney Swans for another two seasons.