Rhodes was Boro’s highest profile signing of the January transfer window, arriving from Blackburn Rovers for a £9 million fee (BBC Sport).
However, despite his hefty price-tag, Karanka insists that the Scotland international striker has already been told that he has a fight on his hands to earn a place in his starting line-up.
“Jordan is a player who everyone would want to sign but he decided to join us," the Spanish boss said.
“It’s a big step in his career and for me it’s important that a player like him wanted to join us because it shows we’re doing something well.
“He knows after my chat with him that he’s coming to a team and no one is above the team. He told me he’s coming to add to that and is really pleased to be here.
“I think he’s a goalscorer, he knows the league and everyone respects him.
“I can understand how pleased everyone is, but I have to say that we have a much better squad than we had one month ago which the main thing is for me."
Rhodes has been brought to Middlesbrough, as the North East side look to ensure that they are promoted to the Premier League.
Boro are currently in the automatic promotion spaces in the Championship, but they have not rested on their laurels.
As well as signing Rhodes, Karanka’s side also brought in Ritchie De Laet, Julien de Sart, Gaston Ramirez and Kike Sola in January.
The new arrivals have considerably strengthened every area of Middlesbrough’s squad, as they look to catch top of the table Hull City.
Boro’s next match comes against Blackburn, with Rhodes looking set to make his debut against his former club.