Arsenal boss Mikel Arteta has admitted he was not aware of Kai Havertz's disciplinary issues.
The German has now picked up his eighth yellow card of the Premier League season.
He collected the caution in the 2-0 win over Luton Town on Wednesday, with Arteta aware that a couple more will result in a two-match ban.
"Yeah we have to careful. Hopefully he won't get booked again because we know what happens with the 10th," Arteta said in his post-Luton press conference.
Arteta replied on whether he was surprised that Havertz had this issue: "Yeah. If you told me another player, maybe not, but with him yeah.
“I will have to go back and look at those yellow cards, but if they are yellow cards then we'll have to improve because we don't want our players having that many because we are the best in the league for that. It's something to improve."
