The Gunners are currently third-placed 11 points behind league leaders Leicester with a game in hand on the Foxes.
"It's not totally over yet," he told German website sport1.de. "If we win all of our matches, then we've got a good chance.
"We've got to keep focusing on that and that's why we're taking things game by game.
"We're trying to concentrate fully on our next game against West Ham. We have a bit more time now that we're not in any other competition so we don't have to concentrate on anything else, other than the title."