The Indian team did extremely well in the fist half of the season and was a strong contender for the fifth position in the championship but now even sixth is on the edge.
The tyre change post the Silverstone blowouts hit Indian outfit the most as after that it has managed to score just three points in seven races while in previous eight they had scored 59.
"We have probably sacrificed the fifth position in the championships to be at least fifth next year. That how I see it," he added.
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"On paper it looks very tough. But we will work together, we came here prepared as normal. Hopefully we have successful Friday and Saturday. We need to do our job right. No mistakes, then only we can keep our (6th) position. We have to keep fighting," the Scot said.
"I think it (tyre change) has definitely affected our performance as a team more by the tyre change than most people, and both Ferrai and Lotus would be agreeing with us where we are," Di Resta added.
"Improvement (in the car) I would say is unlikely but getting the car balance is key to success at the moment. We were trying to get things back before the Suzuka. We have an idea where to work on the car," he said.