Argentina coach Edgardo Bauza believes a "very angry" Lionel Messi was reacting to criticism by not celebrating his winning goal against Leganes.
Messi completed his brace with a penalty in the 90th minute to see Barca edge to an unconvincing 2-1 win in LaLiga on Sunday.
But the Argentina star did not celebrate his goal, with his team - and coach Luis Enrique - having been jeered during the encounter.
His national team coach, Bauza, said it was likely a response to the criticism Messi received in the wake of the 4-0 Champions League loss to Paris Saint-Germain.
"I think he reacted to the criticism he may have received after PSG," he told radio show Joga Bonito.
"I noticed he was very angry when he scored the goals."
Barca's win saw them move within a point of LaLiga leaders Real Madrid, who have two games in hand.