Vella made his first grade debut for Parramatta against
North Queensland in Round 11 1998 at
Willows Sports Complex. Vella was selected to play from the interchange bench for
New South Wales in Game II of the
1999 State of Origin series. At club level, Vella was selected as the Dally M rookie of the year in 1999 and played 24 games for Parramatta as the club reached the preliminary final against Melbourne. Parramatta went into the break leading 16-0 but lost the match 18–16 at full time. At the end of the season he helped the
Australian national team to victory in the final of the
1999 Tri-nations tournament. After that he represented Australia during their successful
2000 World Cup campaign and the following year went on the
2001 Kangaroo Tour. Vella played for the
Parramatta Eels at prop forward in their
2001 NRL grand final loss to the
Newcastle Knights. In 2005, the rugby league world was shocked to learn Vella was fighting thyroid cancer. Vella returned to the field midway through the 2005 season and was part of the Parramatta side which won the minor premiership that year. Parramatta went into the 2005 finals series as one of the favourites to take out the premiership but suffered a shock 29–0 loss against North Queensland in the preliminary final. Vella played in the match from the bench. After time out of the game, he returned to the field for the Eels in 2006. Vella's final game for Parramatta was the 12-6 qualifying final loss against Melbourne. Vella then headed to England to play in the
Super League for English club
Hull Kingston Rovers where he was voted Players' Player of the Year in 2007. He also captained the club in his final year, 2011. ==Post playing==