Reports have been rife in England this week that Frank Lampard’s side have agreed a deal with Leipzig for the 24-year-old Germany international.
It has been reported that Liverpool, who were Werner’s preferred destination, were unwilling to part with the £54m that would have released the former Stuttgart forward from his contract, leaving Chelsea as the frontrunners for his signature.
However, in an interview with Sky Sport, Mintzlaff denied reports that discussions have been held with Chelsea.
Mintzlaff said: "We are concentrating on the final sprint of the league. We want to go to the Champions League. That is the only thing we are currently discussing with Timo.
"It was important for us that we extend the contract with him. We did that last summer, because of course it is important for our young club that no player moves free of charge.
"Of course, there was this exit clause that we put in the contract to give him the opportunity to take the next step.
"Now Timo Werner is sitting in the driver's seat, not us anymore. So far, Werner has not exercised the clause, nor has any club sent us a transfer contract.
"We haven't had an exchange [with Chelsea] yet. Accordingly, we have nothing to report. Timo Werner is a player for RB Leipzig. He signalled a few weeks ago that he was busy with a transfer. Right now nothing is dry."
Werner has scored 25 Bundesliga goals in 30 games this season, helping Champions League quarterfinalists Leipzig to third on the table.