Mauricio Pochettino came under fire for resting key personnel in the defeat to Sunderland last time out, while the Hammers are unbeaten in their last four Premier League games
The Argentine came under fire for resting the likes of Jay Rodriguez, Artur Boruc Jose Fonte and Morgan Schneiderlin for last weekend's fifth-round 1-0 defeat to the Black Cats.
|WEST HAM LATEST
|4/1||West Ham are 4/1 with Paddy Power to beat Southampton to nil|
"The first thing I want to make clear is we've always shown proof that we fully care about the English competitions," he said.
"Particularly the FA Cup and League Cup, we've always shown respect. We always choose the best starting XI, we did what we thought was for the club, we made the correct decision in picking those players."
Jos Hooiveld is out with an eye problem, but Pochettino may include Dejan Lovren and Gaston Ramirez as the pair make their comeback from ankle injuries.
The match also represents the first time the Saints have been refereed by Mark Clattenburg since the club lodged a complaint against the official amid remarks allegedly made towards Adam Lallana in December's 2-1 defeat at Everton.
Cup disappointment aside, Southampton are six games unbeaten in the league while their opponents have won three on the spin and have not conceded in four matches, a run which has seen them climb from the bottom three up to 11th.
West Ham can take confidence from a 4-1 win over Southampton at Upton Park last season, and the fact only one of the last 10 meetings between the sides has resulted in an away win.
The hosts will be without Andy Carroll, who serves the last of a three-game ban for striking Swansea City's Chico Flores, but manager Sam Allardyce believes Saturday's game provides a chance to continue their momentum and boost their chances of survival.
"We've got to try and maintain the run of results that we've had," he said. "Saturday will be a tough game and a big test for us. We're looking forward to the game. We're a long way from being safe, a long way.
"There's a long way to go in terms of trying to get safe so we must try and maintain the good run of results we've had over the last few weeks."