Manchester City defender Eliaquim Mangala has stressed that not even big-money signings Raheem Sterling and Kevin De Bruyne are guaranteed a starting berth due to the club's strength in depth.

The Frenchman made a sublime start to the season but the arrival of Nicolas Otamendi from Valencia has Mangala looking over his shoulder.

Nevertheless, Mangala has insisted that he is not the only player who faces stiff competition at City.

"Otamendi makes the team stronger and I know Nico really well, because I played with him at Porto. I know his skills and his level. If you are not giving your best, he is there [to take your place]," Mangala told UEFA's website.

"It is the same with every player. We bought Kevin De Bruyne, we bought Raheem Sterling, so it is the same for the forwards. They know they must perform because if they do not they will be replaced."

Mangala endured a difficult first season at City after joining from Porto in 2014, but he has made it clear that he feels confident at the Etihad Stadium now.

"My first season was a transitional year. It was very similar to the first season I spent at Porto. The only difference was the importance it assumed because I'd become a higher-profile player because of my transfer fee and the club I had joined. I'd reached another dimension," the centre-back said.

"But having that experience at Porto helped me put all the media, press and TV attention aside, and I could say to myself: 'No worries, take your time, no problem, you have a long-term contract, you will learn, you will get to know the league.'

"At the end of the season, I played in the last six games and I felt very confident and comfortable. Now I feel very comfortable and I know exactly what the Premier League is about."