Tunney said he'll support the team's application to the Landmarks and Chicago Plan commissions if they make those changes to the $500 million proposal.
The landmarks commission is expected to consider the Cubs' application during a special meeting on Thursday morning.
The proposed jumbotron is 6,000-square feet, and the proposed pedestrian bridge over Clark Street would connect the Friendly Confines to a hotel.
A Cubs spokesperson said both the jumbotron and pedestrian bridge are needed to finance the project without public money.
