O'Brien excited about West Ham transfer plans
O'Brien is sure it will herald an exciting new era for the club.
"I think it can only mean good things for the club when you move into a stadium like that," O'Brien said. "You can attract players and supporters from all over the world to play and watch there.
"If the club want to push on and to finish higher in the league, then we need a bigger stadium and to fill it to get the revenue into the football club. It's a great step forward.
"Looking at the stadium when the Olympics were on and seeing what the club want to do with it by turning it into a football stadium, it looks unbelievable."