"All the careful things are already done. Now it's about putting him on the grass at the right moment, but he's pushing because he really wants to. "We have respected the timeline and we have done everything. "Bukayo is a massive weapon that we have. We know the impact he has in the team and how important his role and contribution is to our success." Arsenal are second in the Premier League, 12 points behind leaders Liverpool with nine games remaining. Defender Riccardo Calafiori faces a spell on the sidelines with a knee injury sustained on international duty for Italy against Germany on 20 March. "It could have been much worse," said Arteta. "Hopefully it's going to be a matter of weeks, but we have to see how the injury evolves." Andrea Berta, Arsenal's new sporting director, was present at Monday's news conference after he was named as Edu's successor this week. Arteta said the Italian Berta had "many options" from other clubs but was "positive" about joining Arsenal.