Neymar and Luis Suarez took over in Messi's absence, leaving Barcelona tied on points with Real Madrid, which plays at Las Palmas later Saturday. Neymar scored two goals and Suarez one, while Rafinha and Arda Turan added the others at El Molinon Stadium in Gijon.
Barcelona and Madrid lead by two points from Sevilla, which plays at Athletic Bilbao on Saturday.
Messi couldn't play because of a groin injury in the 1-1 draw against Atletico Madrid at the Camp Nou last week. He will miss at least two other games; at Borussia Moenchengladbach in the Champions League and at Celta Vigo in the Spanish league. He also will not play for Argentina in World Cup qualifiers against Peru on Oct. 6 and Paraguay on Oct. 11.
Coach Luis Enrique filled the midfield with Turan, Rafinha, and Andre Gomes, resting Andres Iniesta and Ivan Rakitic.
Sporting played with 10 men from the 74th as captain Alberto Lora was sent off for a second yellow card after a hard sliding tackle on Sergi Roberto.