London - Old friendships and any lingering effects of a virus will be forgotten on Saturday when Aston Villa visit Premier League leaders Chelsea at Stamford Bridge.
After suffering their first defeat of the season, 3-0 at home to Arsenal when Villa were missing three players due to illness, Paul Lambert's third-placed side are seeking a return to the resilient form that helped them secure successive 1-0 wins at Stoke City and Liverpool in the opening month.
But Villa goalkeeper Brad Guzan says inflicting Chelsea's first defeat will require fitness, concentration and the right attitude.
The American international was in goal when Villa grabbed a 3-1 win at Chelsea in December 2011, a result that dented the London club's title challenge and contributed to the departure of manager Andre Villas Boas.
"At Stamford Bridge, you have to give yourself a chance to win the game," Guzan told reporters. "What I mean by that is you have to be up for it, from the very first minute.
"You can't give them an inch because if you do, they will take a yard.
"I have been on teams with Villa where we have done really well and picked up some great results there. It takes focus, industry, graft, determination and skill to come together."
Guzan was also in goal in December 2012 when, in Lambert's first season in charge, Villa were hammered 8-0. That represented a record-equalling win for Chelsea who this season have shown similar attacking elan.
After five games in which Spain midfielder Cesc Fabregas has oozed creative class and striker Diego Costa has struck seven times, Jose Mourinho's team have scored 16 goals.
But they dropped their first points last weekend in a 1-1 draw at champions Manchester City.
Despite what promises to be a busy afternoon, Villa's Swiss defender Philippe Senderos is looking forward to a reunion with Fabregas, a man he regards as 'a brother'.
Senderos, 29, shared 'digs' with Fabregas, 27, for three years when the pair arrived at Arsenal as teenagers and they have remained close friends. "Without his help, I don't know if I'd have settled so quickly," said Senderos.
"He didn't speak a word of English when he moved to Arsenal. So I was next to him and trying to help him in everything he needed. But he picked it up pretty quickly," he told the Villa website (www.avfc.co.uk).
"He is a terrific player. He speaks on the pitch better than anyone. I'm pleased for him that he is doing well at Chelsea. His dream was to go back to Spain and play for Barcelona in his home town...
"Now, he has a fantastic environment where he can develop at Chelsea... He is really happy."
In contrast to Fabregas, former Chelsea forward Joe Cole is still waiting to make his Premier League debut for Villa after an injury-hit start with his latest club.
Cole, 32, won three titles in seven seasons with Chelsea before arriving at Villa in July via Liverpool, Lille and his original club, West Ham United.
Once seen as the boy wonder of English football, Cole, back in full training after a thigh injury, would love to play at Chelsea.
"There's never a good time to be out, but mine has come at the start of the season with my new club," he told Villa's website (www.avfc.co.uk). "Obviously, I want to go out on the pitch and make an impact.
"But, it's a long season and there are lots of games to play. I don't want to rush it."