Sony Espn's video: John Stones I must earn my starting spot at Manchester City

John Stones insists he will have to be at his best to keep his place in the Manchester City side. The 22-year-old defender was thrust into the starting lineup for City's Premier League opener with Sunderland on Saturday -- just four days after completing a £47.5 million move from Everton. However, City boss Pep Guardiola has already shown his ruthless side by dropping England keeper Joe Hart to the bench and leaving out Yaya Toure, Wilfried Bony, Eliaquim Mangala and Samir Nasri from the 18-man squad that faced the Black Cats. Hart has travelled with the squad to Romania, but the others have been left behind in Manchester and Stones says nobody can feel secure of a starting place at the Etihad. Speaking ahead of City's Champions League playoff first leg with Steaua Bucharest on Tuesday, the England international said: "I know I've got to fight for my place and show everyone what I can do and earn my place. "And that's what I'm here to do -- work hard in training and show the gaffer what I can do and earn that starting spot." If Stones starts against Steaua, it will be his first appearance in the Champions League. The defender said his current situation is why he was so keen to make the move to the Etihad, and added that City will be ready for their Romanian opponents as they try to secure a place in the group stage. "You don't get these opportunities to work with the best manager in the world and at a top club and in the Champions League. I feel now was the right time for the next step in my career," Stones said. "We treat everyone with the same respect. We look at everyone's strength and weakness. We work hard and the gaffer works hard to study what other teams will do against us."