The Blues have already spent almost £50million to sign Germany striker Timo Werner from RB Leipzig and £36m on Morocco international Hakim Ziyech.
Chelsea owner Roman Abramovich has also sanctioned a £90m deal for Kai Havertz and a £50m move for Ben Chilwell, with both closing in on transfers to Stamford Bridge.
Brazilian defender Thiago Silva is also expected to join Chelsea on a free transfer, having ended his eight-year spell at PSG at the end of the season.
Given Chelsea’s transfer business, Poyet says a repeat of last season’s fourth-place finish will not be acceptable for his former club.
‘Now we are coming to a moment when it looks like Chelsea are really going to invest,’ the former Chelsea player told Sky Sports.
‘It changes the parameters completely from last year. Last year was a transition year, ‘let’s see how we do’, and it was very good.
‘With the possibility of all these players coming in now, Chelsea needs to aim top two, if not winning the league.
‘How ambitious he (Lampard) is, I think he would prefer this, I think he would prefer players coming in and going for the big possibilities.
‘I don’t think he wanted to be at Chelsea just playing with young kids and being allowed not to win trophies.
‘I think Frank wants to win trophies and these kinds of players will give him the chance to get closer.’
On Chelsea transfer target Thiago, Poyet added: ‘I think he is top. I know he’s 35, I think you need experience.
‘The teams that, as a club they have a strategy to go with young people, they (also) try to keep a line of experience, the goal keeper, one of the centre halves, one of the midfielders and the striker.
‘They don’t go young everywhere, so that helps you to make the others more comfortable.’
Chelsea begin their 2020-21 Premier League campaign on September 14 with a trip to Brighton.