David Moyes is not expecting a repeat of the disturbances that marred West Ham's last home fixture against Burnley, but insists his players are "prepared" and "mentally stronger" if more incidents happen at London Stadium.
Five supporters were banned for life by the club after a series of unsavoury incidents during the 3-0 defeat to prior to the international break.
Several fans invaded the playing surface, while a coin struck co-chairman David Sullivan's glasses during a toxic atmosphere.
Captain Mark Noble tussled with one supporter, and West Ham confirmed a number of changes to security at their stadium for when fellow Premier League strugglers Southampton visit this weekend.
But Hammers boss Moyes, whose side are one place and two points above 18th-placed Saints, is sure the fans will get behind the team.
"I think the atmosphere will be great at our stadium," Moyes told a news conference.
"It has been great, with the exception of one occasion, since I've been here. I've got no worries about the supporters.
"The supporters are right behind the team here and I still think they are right behind the team and I think they will show it as well.
"Our first-half performance [against Burnley] was really good, but I've got to say Nick Pope made two fantastic saves which probably altered the game.
"Burnley started the second half better, got the goal and then things changed. It was a dramatic change not just because of the goal but because of the whole atmosphere which the players didn't enjoy.
"But we're prepared now, the players are prepared. If it happens again and we get in that situation we'll be much better, we'll be mentally stronger and hopefully do the right things."