Shkodran Mustafi believes Arsenal can still win the Premier League title, despite Saturday's defeat at Chelsea leaving his side 12 points behind the runaway league leaders.
But Germany international Mustafi insists Arsenal - who host Hull City in the Premier League on Saturday - will continue to battle for their first league title since 2004.
"I think it's going to be more difficult than it was before, but I'm a believer," he told Sky Sports News. "I don't give up.
"As long as it's possible we're going to fight for it, and in the end we will see and if we're lucky enough and good enough to go for it or not."
Mustafi accepted Arsenal's recent displays have been below-par, with five goals conceded in their last two league matches.
"The first game we lost at home [to Watford] was really disappointing," Mustafi said. "We woke up a bit late, conceded two quick goals and it was difficult to come back.
"We were disappointed as well with losing at Chelsea, which was a completely different game. We knew it would be difficult at Stamford Bridge, but we knew as well it's possible to win. I think in the end we didn't do enough."