“You have now examples already of clubs investing and making important movements in the market and we are still nine matches away from the end of the season,” he told reporters on Thursday.
Tottenham Hotspur will not be in the same league as other leading English clubs in terms of transfer market spending in the next window, according to manager Jose Mourinho.
"You have now examples already of clubs investing and making important movements in the market and we are still nine matches away from the end of the season," he told reporters on Thursday.
"We know that we are not going to be in the same league, in the same world, as clubs that are going to do completely different to us.
"But would I expect us not to do anything and to stay exactly with the same squad that we have in this moment? My answer is no," he was quoted as saying by the BBC.
Chelsea made the first major transfer move ahead of next season after reaching an agreement with RB Leipzig striker Timo Werner.
British media said Chelsea triggered a 50 million euros ($56 million) release clause to get the Germany international.
The west London club in February wrapped up a deal to bring in Ajax Amsterdam's Morocco winger Hakim Ziyech for 40 million euros and he will arrive in the summer.
Manchester United in January splashed out 55 million euros on Sporting's Portugal midfielder Bruno Fernandes.
However, Mourinho said Tottenham's approach to buying players in the window would be "very balanced" as usual.
"I expect us to do some little important things and if we do our little important things and we improve in two, three positions that we need to improve in the squad, I am completely open to the challenge," he said.
"I am completely supportive to the board, to the owners."