Graham Potter admits Chelsea must improve after their heavy FA Cup defeat to Manchester City, as he came under fire for leading the club to just two wins in nine games.“The results in a small space of time are not positive,” he said. “You can make excuses and look for reasons or say it isn’t good enough. Both of those answers are correct.“We have to keep improving and stick together because clearly we are suffering as a football club and it’s not nice at all. But that’s where we are at the moment."