Brad Guzan has dismissed Aston Villa's thumping defeats by Chelsea and Tottenham Hotspur in their past two matches as "one or two bumps in the road" and said the players remain confident in their own ability as well as Paul Lambert's methods.

Villa's 4-0 defeat at home against Spurs on Boxing Day, three days after they were subjected to a humiliating 8-0 hammering at Chelsea, leaves the Midlands club are fifth from bottom, with the worst goal difference in the league, before they face their fellow strugglers Wigan Athletic on Saturday.

The manner of those defeats has raised fresh questions about Lambert's decision to place so much faith in youth this season, even though the Villa manager remains adamant that his players will "be fine". Villa picked up two hugely impressive results earlier in the month, at Norwich in the Carling Cup and at Liverpool in the league, but they have been brought back down to earth with a bump. The statistics tell their own story: Lambert's team have scored the fewest goals in the top-flight and only Reading have conceded more.

Guzan, however, believes the Villa players must look at the bigger picture. "Just because you have one or two bumps in the road it doesn't change what we are trying to do or the personnel. You have to stick together and keep fighting," said Guzan, whose form in goal prevented Villa from even heavier defeats against Chelsea and Spurs.

"We are confident in what we are doing as individuals and as a club. We are confident in what the coaching staff and the manager are doing on the training ground. We know there is going to be criticism but at the same time we are confident we can put it behind us. We have to."

An injury crisis has not helped Villa's plight – Nathan Baker picked up a hamstring strain against Spurs and has joined Ron Vlaar (calf), Gabriel Agbonlahor (hip), Charles N'Zogbia (knee), Richard Dunne (groin), Andreas Weimann (calf) and Darren Bent (hamstring) on the sidelines — and means that Lambert is likely to be restricted in terms of the changes he can make for Wigan's visit.

Despite Villa's precarious position in the table, there is no suggestion that Lambert is under any immediate pressure from the fans or the board. A number of Villa supporters headed for the exits with 17 minutes remaining against Spurs, when Gareth Bale scored his second and the visitors' third, but the sound of Lambert's name being chanted in the closing stages provided evidence of how much faith some of the fans have in the manager.

"When you are a professional and you lose 1-0 or 8-0 it doesn't matter, a loss is a loss. It stings and hits home," Guzan said. "I know it was not easy for the fans. It was fantastic [against Spurs] to see the amount of the support we had. The game was basically over in the 88th minute and the fans are singing loud and proud – that gives us a bit of a boost. It is not the results we want or they want but at the same time we are in this together. They continue to push us and hopefully we can continue to pick up good results along the way."