Henry, Arsenal's record goalscorer, is on the brink of agreeing a two-month loan deal that will see him back at the club he left for Barcelona in 2007.
The New York Red Bulls striker is just waiting for the completion of paperwork before he is once again registered as an Arsenal player, and is expected to make his second debut in the FA Cup tie against Leeds on January 9.
And ahead of that fixture, Van Persie has paid tribute to the 34-year-old. "It is fantastic," the Dutchman told Arsenal's website.
"For him to come back is something so brave. He has nothing to prove. He has a statue here. Some people might question 'why do you do it, because you have proved everything already?' but there is only one answer. He just wants to play.
"I asked him a couple of weeks ago to come back. He is unbelievable, even in training. I don't want to put too much pressure on him, but he is looking right up there. It will be good for everyone. It is a massive joy to play and train with him. I am excited too. It's like, 'oh yes, Thierry is back, let's have fun'."