England internationals Harry Kane, Dele Alli and Eric Dier are among the players to have been given time off after the tournament, with no participation in pre-season games as a result.
Pochettino's side get their Premier League campaign up and running away at Newcastle United on Saturday and the manager accepts he has difficult team selection decisions ahead.
"[For] the players that were involved in the World Cup, it was massive and so important to give a very good rest and recovery after a very tough season and World Cup and now it’s a big challenge for us to try to provide them with the best tools to be competitive as soon as possible," Pochettino told Tottenham's official website.
"Always we need to assess them. We will see on Monday, Tuesday, Wednesday then Thursday and Friday to take a decision for the team.
"If some players are ready, of course we are going to use them but we are not going to take some risks because sometimes for one game, you lose the players for one month or two months and that is [why it is] so important to be clever in the decisions that we are going to take."
Pochettino previously suggested 21-year-old midfielder Luke Amos could be in line to start against Newcastle.