Arsenal's new signing Petr Cech has warned Chelsea that "friendship goes away once you are on the pitch" ahead of the Community Shield encounter with his former club on Sunday 2 August.
After beating Manchester City for the title at the start of the 2014-2015 campaign, the Gunners will have the chance to revalidate their crown against the Premier League winners after winning the FA Cup for their second consecutive time last season.
Cech may be between the sticks for that opening game after Arsenal announced his signing on Monday 29 June following 11 years at Stamford Bridge.
"I think the script couldn't have been written in a better way for the fans because this will be one of the days [that is] very exciting and very strange at the same time. I have to say, having been with Chelsea for 11 years and having so much success and great memories, I guess it will be a very strange feeling to be on the other side," Cech said to Arsenal official website.
"Once you're on the pitch, you play for your team and you want to win. During the year you can play against friends, you can play against big friends and close friends but once you are on the pitch, this friendship goes away and you just focus on winning the game."
Even though Jose Mourinho had claimed a number of times he wanted Cech to stay at West London, the 33-year-old keeper has insisted that he has decided to leave Stamford Bridge because he wants to fight for the number one role at the Emirates Stadium after last season he lost that role to Thibaut Courtois at Chelsea.
"It was probably the hardest decision for me to go, but last year I realised that I am not in a phase of my career when I would sit on the bench. I want to be playing, I want to have a chance to compete for my position in the team and I want to be useful for the team and do the usual stuff on the pitch week in, week out," he said.
"I hope I will have that possibility to compete for my place here at Arsenal and I hope that I can bring something a little extra to the team that can help."
Meanwhile, Cech has also mentioned the big influence of both Arsenal manager Arsene Wenger and his compatriot Tomas Rosicky in making the move to North London.
"I had a good chat with [Wenger] and it was the first time after the club approached me that I could speak to him in private for such a long time. He made me believe that this was the right step and that this is the club with a lot of ambition. I have a lot of personal motivation and ambition and the club definitely matches it," he said.
"It is an exciting time for me, it is a project where Arsenal fans and the club have been waiting for the Premier League title and this is a chance for me to bring my experience and my little extra to the team and we can possibly achieve that."
And speaking about Rosicky he added: "Yes, we have spoken - obviously we had time together with the national team but at the time I did not know what would happen."
"But he seems happy always and he loves playing for Arsenal. He was excited about the idea that this could happen. He told me a lot of good things and he was one of the reasons why I decided to give it a go and meet with Arsenal. Then the discussions went on and here we are today! I am really happy it happened that way."