West Ham manager Slaven Bilic believes English teams underestimate their opponents in Europe.
The Hammers play Manchester City on Saturday as Manuel Pellegrini's side look to bounce back from losing 2-1 at home to Juventus in the Champions League.
City's defeat contributed to a miserable week for English sides in Europe's premier competition as Manchester United lost to PSV Eindhoven and Arsenal were beaten by Dinamo Zagreb.
Chelsea were the Barclays Premier League's sole success, winning 4-0 at home to Maccabi Tel Aviv.
Bilic led Besiktas to victory over Liverpool in the Europa League last season but his West Ham side failed to make it past the qualifying stage in August after losing to Romania's Astra Giurgiu.
"Why are people so surprised when Manchester United lose a game against PSV?" Bilic said.
"Man United is a bigger club - and they deserved more than a defeat in that game - but many big clubs have lost at PSV. They were European champions 10 years ago (actually 17).
"It isn't a shock. You can lose in Zagreb. It was a major surprise, the whole of Croatia is surprised, but it can happen.
"They play football there as well. They are a decent team, unbeaten in 41 games or whatever.
"They (English teams) are not naive but you have to know that the other teams are also good.
"For you it was probably a shock when Besiktas knocked out Liverpool last year.
"For us it wasn't. A little surprise but we were hoping for that and planning for that to be fair."
City have made the perfect start to their Premier League campaign, winning five out of five games without conceding a goal.
West Ham are in good form too following surprise away wins at Liverpool and Arsenal, but Bilic is expecting a response from City after their Champions League disappointment.
"I would have loved them to win that game against Juventus, they are probably feel a little bit like they need to respond," Bilic said.
"But did it affect their confidence? No, they played okay against Juventus, you have to take that it was Juventus, a team that played in the Champions League final.
"Man City didn't deserve to lose that game, they didn't play great but minimum they deserved a point.
"It was two great finishes. Man City had a couple of really good chances to make it 2-0 but they didn't. They need to respond."