Everton defender Phil Jagielka is disappointed the club have not secured more clean sheets this season ahead of their trip to Chelsea.
The Toffees are renowned for keeping things tight at the back under David Moyes, although they have kept Premier League opposition scoreless just once this season.
Everton shut out Blackburn at Ewood Park at the end of August, however, Moyes' troops still required Rovers to miss two penalty kicks in the game.
Jagielka is not happy with his personal form and is determined to help Everton keep more clean sheets over the next month, starting with their weekend trip to Stamford Bridge.
"Am I happy with my form? No, not really," he told the Liverpool Echo.
"I've given away a couple of penalties which is very frustrating, but I suppose that's what happens if you're a defender.
"I'd love to be standing here and saying 'yes, I'm really, really happy' but I analyse my own game and set pretty high standards and hopefully in a month's time we'll have kept a few clean sheets and if you ask me the same question I'll be a lot happier."
Blues boss Andre Villas-Boas will be without record signing Fernando Torres through suspension, although Jagielka knows there will be plenty more attacking weapons to silence.
"Fernando Torres won't be available because of a suspension but they have plenty of strength in depth," he concluded.