However, Lampard moved to deny reports in Colombia that Chelsea had stepped up their chase by making a formal offer for the £75 million-rated 21-year-old, who has also attracted interest from Manchester United and Bayern Munich.
Asked if he could confirm whether an opening bid had been tabled or if the club were in discussions over signing Havertz, Lampard said: "No, no bids have gone in.
"He's obviously a top player but we are certainly not going to comment on other players at other teams and it cannot be our focus. Nothing to say.
"I don't know [how active Chelsea will be in the market] because we have the games we need to complete before the window opens. That's something we'll broach when it comes round. At the minute, our only focus can be on the games in hand."
Chelsea are also interested in signing Ben Chilwell from Leicester City but a more immediate priority was securing the short-term futures of Willian and Pedro, whose contracts were due to expire on June 30.
They confirmed on Monday that both players will stay for the remainder of the 2019-20 season and while Pedro is expected to join Roma this summer, Lampard has not ruled out the possibility of Willian signing a longer extension, despite the club as yet showing no signs of matching his request for a three-year deal.
"We're still talking with the players and Willian in particular we are talking with him," Lampard said. "It was hard for me to comment too much because it was obviously announced yesterday but I was always confident that they would remain.
"They have been fantastic professionals for the club and servants in all senses. When you have that level of professionalism within, it was a sign that they wanted to stay and see out the season at least. We'll carry on talking and see. But everybody's focus is on these next games."
Chelsea host Manchester City on Thursday night and will be without Fikayo Tomori once again due to a muscular problem while Callum Hudson-Odoi will only be on the bench at best as he is short of match fitness.