His brother Santiago "Aguaviva" Senillosa, is also an important rugby player.
Senillosa made his debut for the national side on April 28, 2002, in a match against Uruguay, and has received 30 caps in total, scoring 128 points (as of September 23, 2007).[2] Senillosa was in the Argentine squad for the 2003 and 2007Rugby World Cups, where he has made 4 appearances in total.[3]
He played all of his amateur sport life as a centre in the Hindu Club. In December 2010, he was suspended by 52 weeks, after a semi-final of the Top 14, in a game with La Plata Rugby Club, after altercations with the referee.[4] He returned to competition afterwards but faced a serious injury upon his comeback. In March 2013, he announced his return to action once again, after an operation.[5]