The 21-year-old moved from Bayer Leverkusen to Chelsea in a £71 million deal in September.
But Bayern Munich also had a strong interest in the midfielder, who was rated as one of the best young prospects in the Bundesliga.
Havertz, however, admits he was swayed by Chelsea’s ambitions and plans to win the Premier League title with a young, attacking side.
‘It was important to me to have a club with a vision,’ Havertz told Sport Bild.
‘An exciting change is taking place. We are a young team with many great players. We think offensively.
‘We want to build something up here and attack. That motivates me a lot. And then it is a title with Chelsea is worth a lot more.’
Havertz also says the prospect of learning from Lampard was a key factor behind his decision to join Chelsea.
‘I was always impressed with his scoring threat,’ said Havertz.
‘The fact that he was so successful and at the same time so personable impresses me.’
Havertz also insists that he is not feeling any pressure from his £71m transfer fee.
‘Well, that’s the way the football market works. I can’t help it. That’s why I don’t put any emphasis on it,’ said Havertz.
‘I try to play football well. I don’t have my transfer fee in my head when I go out on to the pitch.’