Tottenham boss Mauricio Pochettino says new stadium plans could hurt their on-field progress.
The Argentine coach warned fans the club are facing the same sort financial constraints that affected bitter rivals Arsenal while they built the £360m Emirates Stadium.
Tottenham's new 61,000-capacity ground is due to be open in time for the start of the start of the 2018-19 season.
"It's true, we have in front a very tough period," Pochettino admitted.
"Arsene Wenger says the most tough period for the club was in the period when they built their stadium.
"And now I think that you need to know and the people need to know that this is a very tough period for us.
"We need to be careful, because we need to arrive to the new stadium in very good condition - to try to fight for everything and try to show that we are one of the best clubs and teams in the world."