Higuain was linked with a move to the Gunners for much of this summer, but the Argentine eventually swapped Real Madrid for Naples last week in a deal worth £34.5m.
Benitez has confirmed that the forward will play some part against Arsenal in the Emirates Cup this afternoon, while praising the club's hierarchy for completing the transfer.
He told reporters: "Higuaín was one of our targets but we thought it was difficult because of all the comments about Arsenal.
"But as soon as the chairman agreed that it was a real target for us he went for him and, done. In terms of the negotiation and to do the deal it was quite quick. I'm really pleased because he is a top-class player.
"I don't know how long [he will play] but I think that he has to play because he is training well, he is fine, but we'll have to manage it at the time."
Napoli will play both the Gunners and Porto at the Emirates Stadium this weekend, with loan signing Pepe Reina also in contention for a first Azzurri appearance.