Barcelona collected a hard-fought three points against Porto on Wednesday night, a result that made it two wins from two in the Champions League this season.
Lamine Yamal started the match, his first start in the competition. Officially, he played 80 minutes, although he left the field in the 71st minute and surprisingly never returned.
According to Mundo Deportivo, Yamal had to use the toilet during the second half and took the opportunity to leave the pitch during a break in the game.
However, he ended up being sent off for nine minutes, during which time Barcelona were playing with 10 men.
Xavi Hernandez, who later confirmed the 16-year-old was suffering from a stomach problem, ended up replacing him with Marcos Alonso.
Barcelona were officially down to 10 men later after Gavi was sent off in extra time, but Lamine Yamal was lucky enough that his absence did not affect his side too badly. The main thing for the Catalans is that they got the win, which they did.