Hansi Flick confirmed Lamine Yamal was benched for Barcelona's victory over Athletic Club due to a recent bout of illness.
The Blaugrana marched into the Supercopa de Espana final, following a 5-0 rout of Ernesto Valverde's side in Jeddah.
Barca did the damage with four goals during the first half from Ferran Torres, Fermin Lopez, Roony Bardghji and Raphinha, who added a fifth after the break.
Victory was well and truly in the bag when Yamal entered the action as a 62nd-minute substitute, with Flick confirming his absence was not due to a recent hernia issue.
"He had some discomfort the last few days," the Barca boss said of the teenager. "He couldn't train these past few days, which is why he was on the bench.
"It has nothing to do with the injury; it was a stomach problem."
With their 5-0 victory, Barcelona achieved the biggest win by any team in a single match in the history of the Supercopa de Espana.
It is also the first time that three different players have been involved in three goals in the competition since at least 2010-11 in Fermin (one goal and two assists), Raphina (two goals, one assist)and Bardghji (one goal and two assists).
On the game, Flick added: "I really appreciate what I saw. We kept a clean sheet again, and that's very good because it gives us confidence in defence.
"We saw a different mentality and attitude, and I really liked seeing how we played as a team, both in attack and defence. It's been really good to see that.
"We were very well-connected, in the right positions and creating chances. That's what I like to see and, also, the goals were incredible."
Shmonny
23
9 yrs 6 months left 🤣🤣🤣