Alan Pardew conceded that he failed to properly account for the absence of Moussa Sissoko as Newcastle United lost 4-1 at Arsenal on Saturday.
Sissoko was suspended for the encounter at the Emirates Stadium and the Magpies suffered without the France international, as Arsenal dominated in a largely one-sided affair.
Olivier Giroud and Santi Cazorla were both on target twice for the north London club, with Ayoze Perez's 63rd-minute strike a mere consolation for Pardew's men.
The 53-year-old later admitted that Newcastle missed the midfielder, and he accepted that his team selection was one of the reasons for their heavy defeat.
"You know with Arsenal there's going to be a chance but it wasn't to be," Pardew told the BBC.
"We didn't play well today and they played well. I don't think many teams would have coped with them.
"We were sloppy with our passing, but we've been on a fantastic run and this was always going to be a tough game and it didn't work out for us.
"We play a lot better than that usually. We missed Sissoko and I must look at myself in terms of selection of the team.
"We need to cope without him because he's not going to play every week. We tried to be ambitious and if that's a fault we have to accept that."