Mumbai City FC assistant coach Oscar Bruzon believes the penalty conceded by his team in the first half went a long way towards their 4-1 defeat in their 2015 Hero Indian Super League match against Atlético de Kolkata at the DY Patil Stadium in Navi Mumbai on Sunday evening.Iain Hume scored a hat-trick for the defending champions, including a penalty in the dying moments of the first half that saw the visitors go into the break leading 2-0.“I think we lost the game in the first half. We played well in the second half,” Bruzon told reporters after the game.“The penalty was a big damage to our state of mind. We were confident for the first 15-20 minutes but ATK played well. They were more eager and hungry than us today.”Mumbai beat NorthEast United FC 5-1 in their last game and when asked if the hosts were too keen to score on Sunday, Bruzon replied: “We weren't covering all the spaces in the defence. Hume and [Javi] Lara controlled the game [for ATK].”After a home run of five matches and three successive wins, Mumbai now travel to the Jawaharlal Nehru Stadium in Delhi to play Delhi Dynamos FC who are second in the points table with four wins in six matches. On the prospect of playing Roberto Carlos’ boys on Friday, Bruzon said: “We are going to remain positive. We have an excellent team and we will hold and play well.”