Atletico Madrid slipped back to five points behind Barcelona after failing to seize top spot in the Spanish league.
Atleti had led against Barcelona, only to lose 2-1 to Hansi Flick's side.
According to the newspaper Sport, Rojiblancos coach Diego Simeone chose not to bring on his Nigerian forward Ademola Lookman, even though he still had an extra substitution available.
Simeone kept Julian Alvarez on the pitch for the full match despite the jeers aimed at him. He made his substitutions across three phases but limited himself to just four changes, and the Spider was not among them.
Sorloth came on first, then Hancko and Cardoso, before Jonathan David arrived in the 78th minute. Every change was attacking in nature, given the deficit on the scoreboard, which might well have called for a fifth switch and the introduction of Lookman.
Frenkie de Jong was playing at right-back out of necessity, and Atletico needed to overturn a 2-1 deficit. In any other circumstances, the Nigerian winger would have been the first option.
Not this time. Simeone left Lookman on the bench, an unused substitution still in his pocket.
Lookman is going through a very difficult period, his current level far removed from what he showed during his first months at the Metropolitano. Simeone has stressed this point time and again in his press conferences.
El Cholo is demanding more from the Nigerian, who has scored two goals against Barcelona before. This time he watched his team lose the chance to compete for the Spanish league title without getting a single opportunity to help it.
Atletico need the best version of Lookman. The Nigerian still has plenty of work ahead to win back the Argentine coach's trust.