During Barcelona's Champions League victory over Olympiacos on Wednesday evening, cameras captured Lionel Messi removing something from his sock and putting it into his mouth - but what was it?
Messi took glucose supplement, says Catalunya Radio journalist
The initial theory suggested by Catalunya Radio journalist Ricard Torquemeda is that Messi, who scored his 100th European goal in the 3-1 group-stage win, was taking a glucose pill.
The striker could not later be seen chewing, apparently ruling out the possibility that it was gum.
Why would Messi take a glucose pill so early?
But what stands out is that this took place in only the 10th minute at the Camp Nou; why would the star be taking a glucose supplement so early on in the match?
Torquemeda explains: "Within the first 15 minutes of physical exercise is when the body's muscles are most receptive."
Valverde: "If he took one and scored..."
After the Group D clash, Barça boss Ernesto Valverde was unable to shed any light on the mystery, saying: "Did he take a glucose pull? I have no idea, I don't know.
"If he took one and scored, he should take it again."