The Cameroon international sealed a £15 million move to the Catalan giants this week, ending a seven-year stay with the north London club.
And, despite speaking glowingly of his partnership with Song, the Spaniard expressed his belief that Arsenal's display in drawing 0-0 with Sunderland showed that they have the depth to overcome his exit.
|16/1||Arsenal are 16/1 with Bet365 to win the Premier League
"I felt really comfortable when I played with Alex last year, he was a terrific player, but if he and the club decided that the best option was for him to leave we have to accept it," Arteta told the club's official website.
"I think we are good enough to carry on without him. We are looking good. We looked really organised on Saturday, just maybe in the final third we didn't take the chances we should have done."
New signing Olivier Giroud was guilty of a glaring miss on his Premier League debut as the Gunners were held to a frustrating 0-0 draw but Arteta called for fans to be patient with the club's new faces.
"It will take a while because there have been some new players coming in and we are building a new team," the midfielder continued.
"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."