United will go level on points with Arsenal if they overcome the Premiership’s bottom side and there is a renewed wave of optimism at Old Trafford despite a number of injuries to key players after six successive victories.
Ferguson, however, insists they must keep their foot on the pedal in the race for top spot.
“Players can be motivated very easily in games like Liverpool, Arsenal and European ties but the bread-and-butter matches are also very important,” said the United boss.
“Games like this one against West Ham, who are bottom of the table, are ones you need to win.
“They will come here fighting, knowing they beat us twice last season. I have to make sure we work as hard as West Ham. With the confidence we are showing at the moment we have a chance.
“I have been delighted with the performances of the team and we are now in a very busy period.
“A lot of things become definitive. Come January 1, you’ll get the shape of the top and the bottom of the league going into the second half of the season.
“We want to be in the top part and challenging for the lead. We can look forward to the next three months if we perform properly.”
Ferguson has offered his support to under-fire Hammers boss Glenn Roeder.
“I have been surprised and disappointed that he has come in for some flak.” said Ferguson.
“I have been talking about us needing a break, he needs a break himself. You wonder how a team with their ability are bottom of the league.”
Ferguson admits he is reluctant to change a winning team and England captain David Beckham could again be on the bench after recovering from a rib injury. Rio Ferdinand is again out with a thigh problem but fellow defender Laurent Blanc returns to the squad after a calf strain.
Ferguson looks likely to stick with the central defensive partnership of Wes Brown and Mikael Silvestre.
Brown believes Old Trafford is becoming a fortress again.
“We’ve beaten Liverpool and Arsenal to prove we are still in there with a chance of the title.
“It doesn’t matter who we play, whether it’s West Ham or Arsenal, you approach it exactly the same way.
“We’ve put in some good performances and everyone is buzzing at the moment and looking forward to facing West Ham.”
West Ham club captain Steve Lomas is hoping to have recovered from an ankle injury in time to line out.
If midfielder Lomas fails to make it, Joe Cole will captain the team at Old Trafford.
The game has come too soon, though, for Freddie Kanoute (groin) and Don Hutchison (knee).