West Ham boss Sam Allardyce has stressed he is looking to boost his defence with new signings as quickly as possible.
With James Collins, Joey O'Brien (both hamstring) and George McCartney (knee) injured and a Barclays Premier League home clash with QPR to come for his team on Saturday, Allardyce fielded an experimental back-line in last night's FA Cup third-round replay at Manchester United.
Opting to rest Guy Demel by leaving him on the bench, the manager brought midfielder Alou Diarra into a central defensive trio alongside Winston Reid and James Tomkins, with Jordan Spence and Daniel Potts operating as wing-backs.
Allardyce was pleased with the performance those players produced in a contest United won 1-0, but made it clear he wants to bring in reinforcements swiftly.
The 58-year-old, who is interested in Blackburn full-back Martin Olsson, said: "We will try to get some defenders in as quick as we can.
"Alou Diarra did a fantastic job to help on our defensive side, because in terms of player availability, we only had Winston Reid, James Tomkins and Guy Demel who were experienced defenders.
"Alou Diarra stepped into the middle of the back three and did very well.
"Young Jordan Spence and Danny Potts were playing as wing-backs and they did well.
"But we want to improve the squad and we want to get our injured players back as soon as we possibly can."
Allardyce made six changes to his first XI for yesterday's encounter, in which Wayne Rooney's close-range finish in the ninth minute proved to be the only goal.
West Ham had a penalty appeal for handball against Rafael rejected in the second half by referee Phil Dowd, who then awarded a spot-kick at the other end with just over 10 minutes to go for a similar infringement by Spence, only for Rooney to waste the opportunity by blazing over.
Allardyce was critical of Dowd after the game, saying the difference between the two handball incidents was that "Spence plays for West Ham and the away team, while Rafael plays for the home side at Old Trafford", and suggesting the official "couldn't find the courage" to give a penalty against the Brazilian.
He also looked ahead to the weekend, emphasising the importance of having rested some players for the United match with a view to the QPR fixture.
"You have to change your team accordingly depending on what is coming next," said Allardyce, who along with Demel moved Kevin Nolan, Matt Jarvis and Jack Collison from the line-up that started Saturday's league defeat at Sunderland to the bench yesterday.
"QPR played on Tuesday night (in an FA Cup third-round replay at West Brom), so they get an extra day ahead of it.
"The physical side of the game is massive these days and if you are down compared to the opposition on your physical attributes, it makes it tougher for you to win. So we have to change the team again on Saturday.
"A lot of the players who played against United will play again, but some have been rested, some will hopefully have recovered from injury and we will try to get the strongest side out that we can and see if we can get three points."
One player given a full breather was Joe Cole, who had set up both of West Ham's goals in the original 2-2 draw with United at Upton Park but was left out of the squad completely last night.
Regarding the 31-year-old midfielder - back with his first club having joined the Hammers from Liverpool earlier this month - Allardyce said: "We left him out because he is not ready to be playing Saturday, Wednesday, Saturday.
"It would be unprofessional of me to think after he has just come from Liverpool that he could play three games in one week - it would risk him fatiguing and getting injured.
"So we left him back at West Ham to make sure he has had a full recovery and is available for Saturday."