The youngster was spotted in the crowd at Camp Nou for Barcelona's first home match of the 2019/20 La Liga season as they took on Real Betis on Sunday.
He was sat with his dad, who was unable to play due to injury, and fellow injured teammate Luis Suarez when the action turned dramatic during Barcelona's 5-2 victory.
Messi junior suddenly thrust his arms out and appeared to yell "goal" - much to the shock of Suarez.
After initial reports that the young Messi was celebrating a Real Betis goal, it is now understood that his theatrical reaction came about after a Barcelona attempt on goal hit the side netting and he thought it had gone in.
With more than 1,100 goals between them, Messi senior and Suarez clearly know where the goal is and were unmoved until they saw the boy's reaction and Suarez turns to question his actions. The video has since gone viral.