Arsenal manager Arsene Wenger has admitted that he did not know that Manchester United striker Anthony Martial was available in the transfer window.
The 19-year-old made the switch from Monaco to Louis van Gaal's side despite Wenger claiming he was unaware the Ligue 1 side were willing to part with the player.
"I thought they would not sell him this year because they had sold so many other players. The amount of money was massive but Monaco could have sold him next season instead," Wenger told reporters.
"They said they would not sell him and I thought they were not in any need to sell and would maintain their word.
"I was surprised they sold him. Only an exceptional amount of money would do it."
Wenger's only outfield signing of the summer was goalkeeper Petr Cech, who sat out Tuesday's Champions League defeat at the hands of Olympiacos.