Mikel Arteta said Arsenal need to learn to be ruthless against Manchester City after Nathan Ake's goal earned Pep Guardiola's men a 1-0 win in the FA Cup fourth round on Friday.
The sides will meet twice more in the next three months in the Premier League with the title on the line. Arsenal lead City by five points at the top of the table, and Arteta believes the Gunners have to put the defending English champions to the sword when they have the chance.
The Arsenal boss showed a first league title in 19 years is his priority by making six changes, with Martin Odegaard and Gabriel Martinelli among those left on the bench.
But the visitors still had chances early on as Takehiro Tomiyasu and Leandro Trossard, on his full debut, forced Stefan Ortega into flying saves. "Really disappointed.