The England international joined Arsenal from Southampton as a 16-year-old and has since gone on to star for club and country.
Walcott scored twice at West Ham United on Boxing Day and Rosicky says he has matured into a major attacking force.
Since I joined Arsenal - Theo came six months earlier than me - I've seen him grow from let's say the kid when he arrivedTomas Rosicky
“The goalscoring threat is the main thing with Theo,” he told Arsenal Player. “You can see he is a very good finisher. Since I joined Arsenal - Theo came six months earlier than me - I've seen him grow from let's say the kid when he arrived.
“You could see that he would be good finisher [then], which is what he's showing now. He's a real threat in the box, he's got an eye for the goal so it's very good to have him back because you never have enough guys like that.
“And the same counts now for Podolski who is different type of player but he's got the nose for goal. Guys like that, with a smell for a goal, you can never have enough players like that so it's very good to have him back and for the boss to have another option to the attack. That's very positive.”
Sunday’s opponents, Newcastle United, have taken more points than any side since the start of November but Rosicky is eagerly anticipating another test of the Gunners’ credentials.
“Obviously it will be a tough game but Newcastle will always give you a good match,” he said. “It will be very interesting, I love these kind of games so I'm very much looking forward to playing them. I think it will be an exciting match.”