Gilberto has issued a rallying cry ahead of Sunday's Premier League clash with Manchester United by declaring Arsenal can still win the title. The Gunners trail United by six points with five games remaining and must win the league if they are to avoid a third successive season without silverware, after defeat by Liverpool this week ended their Champions League challenge. Arsene Wenger is convinced his side remain in the hunt and Gilberto, who replaces the injured Mathieu Flamini in the starting line-up, agrees with his manager. 'It's a big game. Maybe things can happen - you never know,' he said. 'The important thing for us is to try and forget what happened against Liverpool. 'We still have a chance to win the title but it's important that we win all five remaining games. If we do that, why not?' Arsenal need to shake off any lingering disappointment from Tuesday's Champions League exit if they are to prevail at Old Trafford. Liverpool sent them tumbling out of Europe with a thrilling 4-2 victory at Anfield and Gilberto has urged his young team-mates to lean from the experience. 'Sometimes you learn more in defeats and nights like Tuesday than when you win,' he said. 'But of course no-one at this club enjoys it when we lose or miss the opportunity to play in a Champions League semi-final. We will all learn from this result.' Flamini's injury compounded a heartbreaking night on Merseyside and the French midfielder is expected to return in time to face Derby on April 28 because of his ankle problem. 'I believe Mathieu will be out for three weeks,' Wenger told Arsenal TV Online. 'It's a big blow but Gilberto has a lot of quality and experience and he will come in. Gilberto can help the team recover and focus.' Dutch striker Robin van Persie is available to start against the Premier League leaders but defender Bacary Sagna is missing with an ankle problem.