Unai Emery accepts defender Nacho Monreal is unlikely to be fit to feature for Arsenal in their season opener against champions Manchester City next Sunday due to a knee knock.
Monreal travelled to Russia with Spain for the World Cup and, although he did not suffer any major injuries, he did return late with a slight issue.
Emery, who is preparing for his first campaign in the Premier League, has already suffered the blow of losing fellow full-back Sead Kolasinac for the best part of two months.
Youngster Ainsley Maitland-Niles has deputised following the injury to the Bosnia-Herzegovina international and Emery is keen to given him confidence, particularly as he suspects Monreal will struggle to be fit in time for the visit of City.
"He arrived with no big injuries, but his knee has a little problem and he's training everyday, but not with the rest of us," Emery said.
"He's doing work alone with the physical coach, and running, and we think maybe on Tuesday he can start training with the team.
"We don't want the injuries, but it's one of those things that you can't help. We have players like Nacho, but he arrived late from the World Cup and also has a small injury.
"It's difficult for him to arrive for the match against Manchester City. For us we are trying to help Ainsley play in this position.
"I want to give confidence to all my players in their positions, then he can play in this position as best as possible. My confidence in all my players is great."