West Ham were hit badly in the summer, first was relegation from the Premier League and then rocked by the sale of key stars such as Trevor Sinclair. However one star who was tipped to leave almost put the home side ahead in first half but Jermain Defoe's shot hit the post after a fine save from Paddy Kenny.
Early on in the game Glenn Roader was forced to make a change, Garcia came on for Brevett who had twisted his ankle.
The home side were booed off by the 28,972 crowd after a disjointed display against a team missing their best player in Michael Brown to a knee injury.
Thomas Repka was roped in as an emergency right-back for the injured Anton Ferdinand, an 18-year-old who was due to make his home league debut.
But Ian Pearce returned in defence after injury and suspension, and was soon in the thick of the action.
He was booked for a flare-up with Chris Morgan at a free-kick after Robert Page had received the first yellow card of the game for a foul on Defoe after 10 minutes.
Hammers boss Roeder was then given a major headache when an innocuous slip forced Brevett out of the game after 29 minutes, to be replaced by Richard Garcia. New signing Kevin Horlock was forced to fill in at left-back.
Defoe exploded into action shortly afterwards with a jinking run and shot which beat United goalkeeper Patrick Kenny, but rebounded off his far post in the 34th minute, with Garcia only able to bundle the lose ball wide.
Jack Lester should have done better for the visitors after half time with a snapshot which sailed harmlessly over the crossbar, but Defoe went close at the other end again on 57 minutes.
Matthew Etherington's storming run through the middle created an opening for the Hammers striker, who weaved his way into the box, only to fire a left-foot shot too high.
But the Blades were slowly beginning to dominate proceedings, and Roeder sent on striker Neil Mellor for the out-of-sorts Garcia, who had not had the best of games since coming off the bench.
David James then had to be at his best to save low at his near post after Nick Montgomery had set up Peter Ndlovu.