Rosa was recruited with the number 29 draft pick in the 2004 AFL Draft, hailing from the North Ballarat Rebels. He made his debut for the West Coast Eagles in Round 17, 2005 against the Sydney Swans. He was selected for first two weeks of the 2006 finals, but was dropped for the last two weeks of finals, being named as an emergency for the 2006 AFL Grand Final,[2] which the Eagles won.
The 2007 season brought new opportunities for Rosa, who played 22 games for the home and away season and was selected in the squad to play in both the two games in the finals series. He suffered from shin splints in 2008, restricting him to just 8 games for the season.[3] He returned in 2009 to play all 22 games.
Rosa played his 150th game in 2014 and re-signed with the club for two more years,[4] however, in October 2015, Rosa was traded to the Gold Coast Suns.[5]
In August 2018, Rosa announced his retirement from AFL football after 13 years and 207 games.[6]
After retiring from football Rosa joined the coaching staff at the West Coast Eagles for two seasons, after which he took on the role of Football Operations Manager at Peel Thunder, the WAFL representative side of the Fremantle Dockers. In 2023 Rosa joined the Essendon Football Club as its Talent and Operations Manager, the following year Rosa would take over from his long serving predecessor Adrian Dodoro as Essendon's List Manager.[7]