Speaking on talkSPORT radio, former Chelsea defender Scott Minto said: "Romelu Lukaku is not staying, it's not going to happen. We know that.
"Thomas Tuchel has said it's not about the club adjusting to him, he has to adjust to us. It has clearly not happened.
"Robert Lewandowski would be absolutely superb in the short term. Even if he's on a two-year contract, he might get away with a three.
"He's proven player, proven striker right now. Chelsea are all about the here and now, they have been for the last two decades."
Lewandowski has spoken publicly about his desire to leave Bayern Munich but Barcelona's financial issues could prevent them form signing the 33-year-old.
With Lukaku seemingly on his way back to Inter Milan (possibly on a loan with an option to buy), Chelsea could look at Lewandowski as a short-term replacement.