Chelsea might have an insider agent that could make this transfer happened despite the long term contract.
The fact that a player increased his contract send 2 messages: whether you forgot about the transfer or you pay more! In this situation Chelsea will pay more imo to get him.
Chelsea must put more effort to make it happen. I think that with the current squad is good enough as long as graham can use all of resources that available for the best.
It is true that the transfer of players must be approved by the club first. because as you said since the player is still under contract, and there
have been rumors that Christopher Nkunku will move from Leipzig for a long time. But Leipzig always refuses incoming offers, because Nkunku is
a key player for Leipzig. But if Chelsea are serious about signing Nkunku they will have to be willing to spend a lot of money, considering that
Nkunku has just extended his contract until 2026. I believe Chelsea with the new owners have very strong financial strength, So like the issue of
price is not a barrier for Chelsea. Besides, I'm sure if Chelsea dared to make a very big offer, then Leipzig will accept the offer.
Leipzig also actually has quite a lot of forwards, so losing Nkunku wouldn't really be a big deal for Leipzig. I honestly agree with your opinion,
Chelsea don't need to spend a lot of money to buy strikers. Because Chelsea already have Aubameyang as a striker, so actually Chelsea's squad is
solid enough, it's just Graham Potter's job to find an effective strategy.