Arsenal defender Per Mertesacker has admitted he has struggled with motivation since winning the World Cup with Germany this summer.
The 6ft 7in centre-back retired from international football after the major triumph but accepts the highs in Brazil have come at some cost to his performances for Arsenal.
He was culpable for Hull striker Abel Hernandez’s goal in the 2-2 draw last weekend and also failed to pick up Anderlecht’s Dennis Praet for the Belgian club’s goal in Arsenal’s 2-1 Champions League victory on Wednesday.
“Personally it is difficult at the moment because that was really a long season last year and to come back from that World Cup and get the motivation back," Mertesacker said.
"I am nearly back, but you can feel there is something missing at the moment. With those games, the belief and the mentality is there, but the motivation will come back.
"We didn't even have time to celebrate [the World Cup win] properly, that was the first thing, but you realise month after month what happened. I am still not there [taking in] what happened in Brazil, maybe in five or 10 years you can really realise what was going on there.
"We came back to Berlin, got on the stage, waved our hands, showed the World Cup and then everyone disappeared to their families to get some holidays, some rest and calm."
Arsenal’s victory in Brussels means the Gunners have qualification in their own hands from Group D but Mertesacker has been underwhelmed with the level of performance shown by Arsene Wenger’s men this season.
“Everyone knows that it was a difficult start for us and our confidence is not that much how we wanted it," he said.
"The character is good, the mentality is good, but football-wise, we lack a few things.
"Our passing game is not as efficient as last year. We are not at our best. We have to admit that, be honest with ourselves and train harder."