Fans have been unhappy with the club's lack of transfer activity last month and held up banners calling for the board to leave in their defeat to Brighton on Saturday.
In a rallying cry relayed to talkSPORT he said: "I ask the supporters, every one of them; get behind the team. Through unity we can turn it all around.
"We don't want to find that a disappointing season has turned into a disastrous one".
The Hammers are currently 3 points off the relegation zone in 12th place.