The Boro head coach used his connections with the Chelsea boss to sign striker Patrick Bamford and defender Tomas Kalas on loan, and believes the Blues will reap as much reward as the Teessiders from the arrangement with Bamford in particular having excelled at the Riverside Stadium.
Karanka told the Northern Echo: “He is a better player now than when he first came to the club. He has achieved the objective that was there at the beginning of the season for him, for us and for Chelsea.
“I think the season has been perfect for him, and the same is true for Tomas Kalas. He came here from Germany, where he had not played a game, but here he played a lot of matches and improved a lot.
“He is happy and Chelsea are happy – and Patrick is the same. He wasn’t really a kid when he came here because he is 21 and was already a good player, but he has taken his opportunity and has improved every single day.
“At the beginning, maybe he played more for himself. But now he is fighting with the team and now he is a different player. He knows how much he needs to work every single game, and he is doing that. He is a quality player.”
Karanka has set his side the challenge of taking maximum points from their final two games to give themselves a chance of automatic promotion.
Boro travel to Fulham on Saturday and then entertain Brighton on the final day of the Sky Bet Championship season knowing even two wins will not be enough to book them a place in the Barclays Premier League if top two Watford and Bournemouth match them, but that is the aim.
Karanka told the Evening Gazette: “We are not under pressure because we are third, so we don’t have anything to lose.
“Our objective at the beginning of the season was to get into the play-offs and we did that two weeks ago, so the pressure is not for us.
“We have to win. We made mistakes against Bournemouth and Watford and now we can’t make more mistakes.
“We need to win both games and we are working to beat Fulham on Saturday, and then we will prepare for Brighton.”