Arsenal's three German players who won the World Cup will miss Sunday's Community Shield and the start of the Premier League season.
Manager Arsene Wenger said on Thursday (local time) that Mesut Ozil, Per Mertesacker and Lukas Podolski had yet to return to training after their success in Brazil.
The trio were given an extended break after Germany beat Argentina in the World Cup final and will miss the league opener against Crystal Palace.
"It's not ideal, but the final of the World Cup was on July 13 and knowing that when they go back to Germany they lose a few days for celebration," Wenger told a news conference before Sunday's (Monday NZ time) clash between last season's FA Cup winners and league champions Manchester City at Wembley.
"They played seven games in the World Cup plus the whole English season, and having the experience of the team that has won the World Cup, it's always difficult mentally to come back and be sharp and hungry straight away again."
The trio are set to resume training on Monday.
Wenger admitted his side were not at full fitness for the traditional curtain-raiser to the season but said he was looking forward to returning to Wembley after the FA Cup final triumph over Hull City, his club's first trophy since 2005.
"It's a good test, it's good to play against Man City because it's an interesting opponent. They won the league last year and it's interesting and exciting for us to go back to Wembley because we were there a few times in May, and in April."
Arsenal beat Benfica 5-1 on Saturday in the Emirates Cup before suffering a 1-0 reverse to Monaco the following day.
Wenger also confirmed that Arsenal had received bids for their club captain, Thomas Vermaelen.
The 28-year-old Belgium international struggled to break into the starting line-up last season, with Mertesacker and Laurent Koscielny forming a strong partnership at the back.
According to British media reports, Manchester United and Barcelona are interested in Vermaelen, who is entering the final year of his contract.
"Look, it could happen, I said at the start of pre-season that Thomas could leave us because he needs to play now," Wenger said.
"He's in a position now where it's difficult to stand in his way if he finds an interesting opportunity."
England forward Theo Walcott, who ruptured the anterior cruciate ligament in his left knee in January, is expected to return to the squad on August 31.
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