London - Chelsea face a stern examination of their championship credentials on Saturday as they travel to Aston Villa. The Premier League leaders have won seven of their eight games so far, but were beaten on their last away outing at Wigan Athletic.
Villa, meanwhile, have been inconsistent this season, but have won two and drawn one at home since losing to Wigan on the opening day.
Michael Ballack is a doubt for Chelsea having played only 45 minutes of Germany's World Cup qualifier against Finland on Wednesday before coming off, apparently feeling the effects of an ankle injury he suffered against Russia on Saturday.
Villa forward Gabriel Agbonlahor, who was booed by his own fans towards the end of last season, goes into the game boosted by a impressive showing for England in their 3-0 win over Belarus on Wednesday.
"Gabby has had a few disappointments along the way - but he has shown a tremendous aptitude which I am delighted with," said manager Martin O'Neill.
"I didn't take him to one side when the fans had a go in one particular game but I never lost faith in the lad.
"I don't think he was ever disheartened, disappointed at times. He will not say a great deal to me. He just nods approval to me just to get me out of the way."
Liverpool also face a tough away game as they travel to Sunderland, who will be buoyed by a draw away to Manchester United on their last outing and will be celebrating the 130th anniversary of their foundation.
Both captain Steven Gerrard and striker Fernando Torres are major doubts following groin injuries.
Champions Manchester United, who lie second in the table, are home to Bolton Wanderers.
Midfielder Gabriel Obertan and full-back Rafael both came unscathed through a 45-minute workout in the reserves on Monday, but are still thought to be some way from first-team action.
Arsenal host Birmingham City, while Manchester City travel to Wigan on Sunday.
Portsmouth, having finally got their first points of the season by beating Wolverhampton Wanderers before the international break, face their former manager Harry Redknapp's present side, Tottenham Hotspur.
They could be without goalkeeper David James, who missed England's game against Belarus with a knee injury.
Second from bottom West Ham United are away at Stoke City.
