Lasarte was born in Montevideo to a Spanish father and an Uruguayan mother, with the former having immigrated from the Basque Country. In his country, he represented C.A. Rentistas (two spells), Central Español, Rampla Juniors (twice), Club Nacional de Football and Defensor Sporting, winning four major titles with the fourth club including the 1988 edition of the Copa Libertadores followed by the Intercontinental Cup.