Arsenal manager Arsene Wenger has hailed his side's "positive" performance away at Hull City, but expressed unhappiness over Alexis Sanchez's missed penalty in the 4-1 win on Saturday.
The Chilean striker bagged a double at the KCOM Stadium, while Theo Walcott and Granit Xhaka also weighed in with goals.
However, the Gunners boss believes that Santi Cazorla should have taken the spot kick as there was an established pecking order among the players.
Wenger said after the game: "I feel overall it was a positive performance after playing away in the Champions League and away again today.
"We started well, dominated and were fluent. They defended well but overall we managed to score the goal then after the missed penalty we had to be serious and score the next goal.
"Santi was down to take it, I don't know why it did not happen, they have a pecking order, it was not planned for Sanchez to take it. I want to know what happened and for it not to happen again."
Arsenal climb to third in the Premier League table following their win.
