West Ham boss Alan Pardew has promoted coach Keith Peacock to replace former assistant manager Peter Grant, who has left to take over at Norwich City.
Grant (left) has departed to manage Norwich City
Reserve team boss Kevin Keen has also moved up and is now first team coach.
"I have always promoted from within, and this enables us to move on quickly from Peter's departure," said Pardew.
West Ham have suffered six consecutive defeats and dropped into the bottom three of the Barclays Premiership after Saturday's 2-0 defeat at Portsmouth.
"Kevin is West Ham United through and through. He cares deeply about the club and has proven himself to be a very able coach during his time here," added Pardew.
"Keith and I go back a long way and, having been involved with us since the start of the season, he is now fully settled in here.
"I am sure both will play key parts in helping us to get back on track."