Rivas joined Inter Milan from Argentine side River Plate and has looked a useful addition to the squad coming from the bench to solidify a lead. Rivas is a mobile central defender who makes strong but often mistimed challenges, with decent overall speed, and good stamina. Rivas looked a good bet for a future starting berth until however a harrowing display versus Sampdoria in the Coppa Italia, where he was given a torrid time by Antonio Cassano until he was then reeled off the field by manager Jose Mourinho by half time. Since then Rivas was afforded limited few opportunities to impress and has since been loaned out to Livorno for the 2009/2010 season. At Livorno he has managed 6 outings, managing 1 goal and 3 cards so far. Rivas has shown a willingness to forage forward, running on the ball to then initiate an attacking play with a pass into dangerous areas. Defensively, his tackles can be heavy and wild resulting in fouls and sometimes injuries. Time will tell whether the former River Plate and Inter Milan defender will manage to secure a starting berth with the Amaranto.