Tottenham Hotspur manager Mauricio Pochettino said it is possible the club could not make any signings as Aston Villa manager Steve Bruce said Spurs have not made an offer for Jack Grealish.
Spurs, who have yet to add to their squad with the window closing at 5 p.m. on Aug. 9, are hopeful of signing Grealish, the England youth international.
"We are working so hard but still, we are like we were on the first day of the transfer window, with no signings," Pochettino said. "I think I'm not the person to explain this. Of course people expect the manager to explain it. But in this situation, for different reasons, it has been difficult to add players who can help us -- but you know in the last week many things can happen.
"Am I relaxed? No, I'm not relaxed. I am a coach and when you are a coach you cannot be relaxed. You need to be confident and trust in the people that you have, and the way we work. But of course, football is always about adding more quality every season like different clubs, our contenders, are doing."
Pochettino said that Spurs "need to try to be creative" if they do not make additions.
"Of course, the help from the younger players would be amazing," Pochettino said. "They showed [in the United States] they can help us if we don't sign players."
Bruce, meanwhile, said at a news conference on Friday that no offer has been extended by Spurs for Grealish, but that talks over a fee "haven't got anywhere near what the owners want to even consider."