West Ham midfielder Jack Collison has backed Robert Green to bounce back from his Bolton howler against Chelsea on Sunday.
The England keeper gifted the Trotters the lead late on at the Reebok Stadium after dropping Gary Cahill's bouncing effort for Ivan Klasnic to tap-in.
West Ham had earlier pulled themselves back into the game when Collison set up Alessandro Diamanti to equalise midway through the second half, but the Trotters then pushed on to win 3-1.
Gianfranco Zola's strugglers next face Carlo Ancelotti's table toppers at Upton Park on Sunday in a game being shown live on Sky Sports 1 and Sky Sports HD1 at 4pm.
Despite the daunting task of denying players of the calibre of Didier Drogba, Collison believes Green has the strength of character to bounce back against the Blues.
He said: "It was a bit unfortunate, and Greeny has been magnificent for us.
"He has played 100-odd consecutive games, and I do not really remember him making a mistake.
"These things happen in football and if it is a keeper, it is highlighted more.
"Greeny is a very strong character and a massive player for us.
"I am sure he is going to bounce back - and what better match than to do it against Chelsea.
"It is a great opportunity to show what a good keeper he is and really claim his place as number one for England."
After the Bolton defeat, West Ham defender Daniel Gabbidon used his personal Twitter site to issue an apology to the travelling fans and Collison insists the players and coaching staff are determined to improve and haul the Hammers out of the drop zone.
He added: "We are not in the greatest of positions at the moment, we know that.
"We are all very realistic and it is going to take a lot of hard work.
"As a team and individuals, we have to cut out the mistakes and do our best to get us out of the situation we are in, work hard, graft for each other then hopefully the results will take care of themselves."