Arsenal defender Per Mertesacker has praised the presence of goalkeeper Petr Cech, who adds his experience to the team's youthful ability.
The veteran Czech Republic international already has four Premier League titles amongst other trophies from his time with Chelsea, and that know-how can help the club's youngsters.
"He has won a lot of titles, including the Premier League," the German centre-back told his club's official website.
"He knows … how to stay consistent and, to get information, advice and opinions from him makes us stronger.
"I realise that this is very important for a squad that is on the one hand young and talented and on the other hand has experienced players who still want to learn a lot about the game.
"Petr is vocal. He wants to speak, he wants to share that information and what a win-win situation that will be for us over the next few years. Having someone like Petr around must be very useful for the club's young players."
Cech is set to come up against his former club when the Gunners face the Blues at Emirates Stadium on Sunday.