Tottenham manager Mauricio Pochettino feels the January transfer window is a "difficult" time to buy players but they cannot be distracted by other clubs' business.
Spurs are yet to make a signing this month and have not bought a player in the previous two winter windows.
Dele Alli was the last player signed by Tottenham in a winter transfer window when he moved to the club for just £5m from MK Dons in 2015 and Pochettino admitted it is hard to bring players to the club in January.
When asked about possible moves for Lucas Moura or Malcom, the Argentine said: "No news. There are a lot of rumours, different names.
"This transfer window is difficult because it's only three-and-a-half months left of competition. It's so difficult to add players now; quality players who can help us to try to win games and achieve all we want.
"If you want players who arrive to the Premier League, you need to know and to be sure if you are going to invest big money.
"All the players need time to adapt for themselves, in a new league or when you change the club and you play in a different philosophy.
"Sometimes you believe it's going to help, and sometimes you are going to create a problem - that is why the transfer window now is so difficult.
"We are always open and I'm so open to adding some players."
With direct rivals Arsenal, Liverpool, Manchester United and Chelsea having made signings this window, while Manchester City look close to bringing new players in, Spurs could be the only top-six club not to reinforce their squad this month.
And, although Pochettino is "aware" of other clubs' transfer activity, he remains unconcerned about it.
"You need to follow your way," he said. "You cannot look next to you, you must believe in the way that you want to create your philosophy and your project.
"Then what is going on next to us - yes, we are aware about that, but you cannot imitate and cannot do what another club are doing now.
"You need to be strong; you need to have personality, character and not be scared about what happens now. Sometimes you can drop a little bit but if you are strong enough, in the future you can win."