With Jonathan Leko not yet fit, and Lukas Jutkiewicz on the verge of returning from injury, Blues are currently struggling for senior forward options, but Karanka insists he will not be rushed.
"The market is in a strange moment, like every single thing in life, when the striker arrives it will be the right striker. We are not in a hurry," said Blues' Head Coach.
"It’s like the property market, the most expensive villas are sold, the cheapest ones are sold and it’s the ones in the middle that are the problem.
"I think it’s going to be the same. The players without contract, a free transfer, can be good for both parties and the big, big transfers.
"Let’s see how the market is in the following weeks, we know how much money we have to spend, and we know the player we can bring with that money and we know the plan."
Karanka also confirmed that he aims to have a final squad size of 23, including three goalkeepers once the transfer window closes: "I would like to finish the market just with 20 players and three keepers because I don’t like to work with a big group of players," he said.
"At the end I like to train with two teams 11 and 11, first and foremost because I prefer to have 20 players with more or less the same level to keep pushing each other and to have that competition between them.
"I don’t want to take two or three or four players out of a training session because I don’t think it’s fair.
"I prefer them to play or if they are young players to go and played on loan because the way to improve is to go and play games."