Career
Nacional
Cavallini began playing for Nacional"s youth development squads since 2010. In June 2011, he participated at the 2011 U-20 Copa Libertadores. His performance was very good, however he could not score goals.
In the third and final game, Nacional drew 0-0 with Universitario, and though, qualified for quarterfinals.
On June 20, they were defeated by Mexican side América 1-0, which lead to their elimination. His outstanding development in the inferiors lead him to sign a senior contract with the club in early 2012.
Juventud
In mid July 2012, he was sent on loan to Juventud de Las Piedras in order to make his debut in first team and have more continuity. In his second match with the club, he scored his first official goal in the 1-0 home victory against Central Español.
On October 7, he was the man of the match against Bella Vista scoring a goal and an assist for his team"s 2-0 victory.
His third goal came six days later, in a 1-1 away draw against Fénix. California Fénix
He joined them permanently before the start of the 2015 Apertura. Lucas launched his international career for Canada at 18 years old, debuting for the U-20 team in 2011 during the CONCACAF U-20 Championship in Guatemala.
Lucas has earned three call-ups to Canada"s U-23 National team and his performance, along with the fact that he "plays in a different type of league (down in Uruguay)," according to Head Coach Stephen Hart, earned him his first call up to the senior roster to face Trinidad & Tobago in a friendly match on August 13, 2012.
Cavallini made his debut for Canada as a second half substitute for Terry Dunfield against Trinidad, the game ended in a 2-0 victory for the Canadians. Cavallini has not appeared for the national team since the disastrous 8-1 loss Canada suffered to Honduras.
He declined a call-up from interim coach Colin Miller for the 2013 Gold Cup, citing "Personal Reasons." Current coach Benito Floro gave an interview in October 2014 where he elaborated on Cavallini, saying that he has reached out to the player and has not heard back from him. Floro however pointed out that there is a place in the team for him in the future.
In May 2015, Cavallini stated in an interview with Tenfield that he regretted becoming cap-tied to Canada.
Despite his comments, Canada announced on October 2, 2015 that Cavallini had been called up to face Ghana in a friendly. In an interview regarding his return to the national team, Cavallini stated that he never said he wouldn"t play for Les Rouges again, and that his comments were wrongly translated. On October 13, after almost three years away, Cavallini returned to the field for Canada replacing Marcus Haber at halftime in a 1-1 draw against Ghana.