Although Lewandowski has reached an agreement with Barcelona to stay with Barcelona until the end of the season or one more season. But Barcelona must move quickly to find a replacement, Barcelona is currently eyeing Newcastle United striker, Alexander Isak, and Viktor Gyokeres from Sporting CP is a more affordable option with a cheaper transfer value.
Barcelona management will not take the risk too quickly to find a replacement for Lewandowski in a financial condition like this. As long as Lewandowski can still be relied on, Barcelona management will look for a replacement player with an easier option such as a player who has free agent status. And in my opinion if Barcelona is eyeing Alexander Isak, it is just a rumor. On the one hand, Newcastle will not release the player at a cheap price and while Newcastle currently still needs the player. So at this time Barcelona can only survive with the existing players and look for a replacement player slowly without rushing which can put more pressure on Barcelona's finances.