After Kolkata Knight Riders lost their opening IPL encounter against Mumbai Indians by 49 runs here on Wednesday, skipper Dinesh Karthik said that rustiness was the reason behind the defeat."I think we had areas to do well with bat and ball. I think it was a pretty rusty day to be honest, I don't want to get too analytical about it but it's ok the boys realise where they could have done better," said Karthik on Star Sports at the end of the match.The match was played in hot and humid conditions in Abu Dhabi which was a change for a number of key foreign players in the KKR squad like Andre Russell, Pat Cummins and Eoin Morgan."Couple of guys -- (Pat) Cummins and (Eoin) Morgan -- just finished their quarantine today. It is hard -- playing in the heat and getting used to the conditions. Don't want to be too analytical, the boys put in a good effort. I haven't had the conversation about that (regarding tweaking the top order) with Baz (coach Brendon McCullum), will let you know by the next game," said Karthik.KKR next face Sunrisers Hyderabad on Saturday.