Liverpool title hopes already hanging by thread
Their 2-0 loss to Chelsea last time out was their third defeat in eight league matches and has left them six points behind the table-topping Londoners.
Another loss at the Stadium of Light, combined with wins for Chelsea at Aston Villa and Manchester United at home to Bolton Wanderers would leave Rafa Benitez's side with a mountain to climb.
Liverpool fans who celebrated their then-record 18th championship title and 10th in 15 years in 1990 would have taken some convincing that 20 years on they would still be searching for their 19th but that is already starting to look a strong possibility even before the end of October.
In recent seasons Benitez has made little attempt to disguise his feelings that the Premier League was strictly a second priority after the Champions League.
While they were winning and reaching the final of Europe's elite competition the fans could just about swallow it but when Manchester United equalled their record of 18 titles last season enough was enough.
Benitez certainly seemed to have more of a focus on domestic duties in the first two months of the season, with less rotation in the league, but his team have still been inconsistent.
They preceded the Chelsea defeat with a loss, and a poor performance, to Fiorentina in the Champions League. They follow the Sunderland game with a Champions League match against Lyon and a Premier League clash with United.
Assistant manager Sammy Lee, a key midfielder in the 1980s when Anfield league titles came along like London busess, told the club's website (www.liverpool.tv) that high-pressure games were the norm.
"At this football club, every week is massive," he said.
"It's been a mixed start to the season - there have been some good points and some bad. But it's still only October and we're going to be working very hard to ensure we're there or thereabouts come the end of the season in all competitions."
Steven Gerrard missed England's World Cup qualifier against Belarus on Wednesday with a groin strain but could feature on Saturday, while Fernando Torres was excused boots from Spain's game against Bosnia having played 55 minutes against Armenia on Saturday.
"There is no window for us to have any kind of international hangover - we don't have that luxury," Lee said.
Sunderland were heading for a famous victory at Old Trafford on October 3. before a last-minute own goal scraped Manchester United a 2-2 draw and, having beaten Wolverhampton Wanderers 5-2 the week before, confidence is high.
United have also been misfiring at times this season, though they have still won six and drawn one of their eight games, but will expect to claim another win at home to Bolton.
Chelsea's win over Liverpool was the perfect riposte after their perfect start to the season had been ended by Wigan Athletic and they face another stiff test at Villa.
Arsenal, who have already scored 24 goals in their seven games, are at home to Birmingham City, Tottenham Hotspur visit manager Harry Redknapp's former club Portsmouth while Manchester City visit Wigan on Sunday.