Thierry Henry has joined Arsenal on a two-month loan from New York Red Bulls.
The former Arsenal captain, 34, has been training with the club during the Major League Soccer off-season.
The forward will play for the Gunners during January and February, while fellow striker Gervinho is absent at the Africa Cup of Nations.
Henry, who is eligible to play in Monday's FA Cup match at home to Leeds, said: "When it comes to Arsenal my heart will always do the talking."
The striker, who had to wait a week to secure the temporary switch while Arsenal finalised insurance arrangements with New York Red Bulls, was famous for wearing the number 14 shirt, which Theo Walcott currently uses. Henry will now be Arsenal's number 12.
Henry added: "I always said I was never going to come back and play in Europe again but, when the team you love and support asks you back, it's kind of hard to say 'no'.
"I am not coming here to be a hero or prove anything. I am just coming here to help. People have to understand that.
"I'll be on the bench most of the time - if I can make the bench, that is.
"Even if it is just five seconds, one second, or just talking in the dressing room, I will give my best whatever it is."
Manager Arsene Wenger added: "I am very happy. It was my desire and Thierry's desire.
"We will have Thierry for January and February, then he will go back to the United States.
"I am sure during these two months he will be a massive asset to the team in the dressing room and on the pitch.
"He can be relaxed, not under too much pressure and be a tremendous help to the team."
Henry will act as a reserve for Robin van Persie, who broke Henry's club record of number of goals in a calendar year in 2011 when he netted 35 times.
"Right now Robin is flying," Henry said. "I can be around and talk to him but he is doing what he does best - scoring goals.
"When the boss spoke to me about coming back, I wanted to make sure I didn't disturb the team that was in place. That was important to me."
The Frenchman will return to the United States to the New York Red Bulls for the new MLS season, which starts on 10 March.