Mauricio Pochettino wants new players and "more quality" brought in at Tottenham before the end of the transfer window.
Tottenham are the only Premier League club yet to sign a player since the end of the 2016-17 season, while the sale of Kyle Walker to Manchester City has depleted their experienced options at right-back.
Spurs' lack of movement in the market drew strong criticism from left-back Danny Rose, who this week urged the club to bring in players that did you do not "have to Google".
Following Tottenham's 2-0 victory over Newcastle United in their Premier League opener on Sunday, Pochettino confirmed he is eager to bolster his ranks.
"The balance is the most important. We need some new players that bring some new energy on the team. It's always important to challenge your best players," he told a post-match news conference.
"For me we need to sign some new players before the end of the transfer window. It's important to refresh the squad. We need more competition between us.
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"We have 10 months ahead of us, we are involved in four competitions that demand a lot of energy and we need more competition, more quality, more players that can help the team to keep the level we want to show in every game."
Tottenham appeared to be struggling at St James' Park until Jonjo Shelvey was shown a straight red card by Andre Marriner for treading on the ankle of Dele Alli.
Newcastle boss Rafael Benitez questioned whether that was more dangerous than Harry Kane's scissor tackle on Florian Lejeune, which resulted in the debutant being withdrawn through injury and was only met with a booking.
Pochettino did not agree, though, and highlighted Matt Ritchie's challenge from behind on Alli too.
"No I think it's different. I saw the action. With the ball in the middle sometimes you can see, but without the ball or in another side it's completely different," he said.
"It's not fair to say they deserve the same punishment - Harry, Shelvey or Ritchie."
The Tottenham manager praised Alli, whose temperament has previously been question, for keeping his cool following the coming together with Shelvey.
"He was calm. That is important. Remember last season we talked a lot about that. How we need to behave and improve and learn," said Pochettino.
"He's mature enough now to accept all that happens on the pitch. He's so calm, so brave. He then scored a great goal.
"He needs to improve. He's not in his best expression, but he is coming."