The New York Red Bulls striker is on loan at the Emirates Stadium for the next two months to coincide with the MLS off-season.
"I never got the chance to meet him before, but he has come back and shown what a true legend he is," Gibbs told the club's official website.
"He has added something to the dressing room, not just on the pitch. We know he can't play every game but his personality has come in and lifted the whole changing room. It is a pleasure to have him in the squad again."
The Gunners travel to Swansea City in the Premier League on Sunday.