"It's up to me now to concentrate on changing my game to suit football in England and concentrate on the ideas of the coach," Rozehnal told the Sunday Sun.
"He (Allardyce) was the most important reason for me to come here, because I heard he wanted to sign me before when he was at Bolton. It's important to be wanted.
"But it was also very exciting for me to show to everybody my quality in the biggest league in the world; to show I am the right man in the right place.
"I hope I work hard enough and do a good enough job during the preparation to be a first-choice in the team.
"It's up to the coach to decide the first XI of course, but I feel better with every game. I will get stronger and stronger and I'll be ready for the first game of the season."
Rozehnal adds: "Borussia Dortmund were the first team to be interested in me this summer, and they are a big club. But then came Newcastle.
"Of course, I knew the coach - as I said, he wanted me before - but also Newcastle are such a big club, with big names and a great history.
"I heard a lot about the city as well. It is famous for being a very friendly place! Of course, it's different from Paris, but I like it.
"The Premier League is a big attraction of course. It's the biggest league in the world without question.
"The last few days before I joined, I heard something about Sevilla as well, but the offer was never as serious as Newcastle or Dortmund.
"I spoke with Petr Cech and other players who have been here as well as my manager; people who know the Premier League well.
"But the most important thing was my own feeling about Newcastle. I liked the challenge."