Sevilla boss Lopetegui hailed Lampard's "extraordinarily strong" team ahead of Tuesday's Group E Champions League opener at Stamford Bridge.
The Blues' chastening 4-1 last-16 second-leg loss to last season's eventual champions Bayern Munich was only back in August, and manager Lampard has since recruited a raft of high-profile new faces.
The ex-England midfielder has been heavily backed by owner Roman Abramovich, with Hakim Ziyech, Timo Werner, Kai Havertz, Ben Chilwell, Thiago Silva and Edouard Mendy all arriving.
Former Real Madrid boss Lopetegui insisted Chelsea already boasted an array of riches even before their summer recruitment drive.
"They already had fantastic players in every position, but now they've added even more," said Lopetegui.
"So they have lots of alternatives in every position, and they have a really attractive football philosophy – they are an offensive side with players that tie into that.
"So for us it's about competing against a team with those characteristics."