"It will take a while because there have been some new players coming in and we are building a new team," Arteta told the club's website.
"We have lost some important players too, so we will need some time. We know that our new players can make the difference as well. We will have to give them a chance to settle into a new place."
Arsenal opened their Premier League season with a 0-0 draw against Sunderland on Saturday.