Everton manager Ronald Koeman believes Sergio Aguero has a mental block when it comes to penalties after he missed yet another spot-kick for Manchester City.
Aguero's penalty woes continued on Saturday as he missed his effort in City's 1-1 Premier League draw with Everton.
The Argentina international has now missed four penalties this season and Koeman questioned the mental strength of the 28-year-old.
"To miss two penalties, maybe it is a little bit of a mental question," said Koeman.
"Maybe for Aguero. I don't know, because it's not the first time that he's missed."
City boss Guardiola insisted Aguero, who also failed from 12 yards for Argentina in World Cup qualifying having missed two spot-kicks in one Champions League match against Steaua Bucharest in August, will remain on penalty-taking duty.
Aguero has scored 11 goals this season as City prepare to face Barcelona in the Champions League on Wednesday.