The 24-year-old midfielder this week completed a protracted move from Huddersfield Town to the Riverside in a deal that could be worth up to £2m.
Clayton joined the Terriers from Leeds in 2012 and is hoping to be handed his first bow in a red shirt this lunchtime.
Karanka said: “Adam wanted to come here since the first minute. It is most important for me when a player wants to join us. It’s the best attitude.
“He is going to improve the squad because he’s a very good player who knows this league and knows some of the players in our squad.
“When you have very good players and competition for places, it is good for the squad.”
Asked if Clayton could start in front of the live TV cameras, the Boro manager replied: “Adam did a complete pre-season with Huddersfield and he is fit. He has a hunger to play and I need to think about that. I have to think very hard.”
Clayton will not be the only man to be facing a club with which he has an affinity with Leeds head coach Dave Hockaday admitting he used to watch Boro as a child.
He said: “I was a fan of Billingham Synthonia and played for them at the tender age of 15. It feels like about three lifetimes ago. But if I wanted to watch one of the big teams then it would be Middlesbrough. I would pop over the river, it was only four miles from my house to Middlesbrough.
“They were my home-town club, really. I do look for their results because they are one of the few teams who I feel an affinity to.
“Things have changed since those days, massively. But they are the form team in the league and we need to be on our mettle.”
The game is likely to come too soon for Spanish defender Damia Abella as he attempts to finalise a move to Teesside after being released by Osasuna.
Long-term absentees Rhys Williams (Achilles) and Muzzy Carayol (cruciate ligament) remain on the recovery trail but are still some months away from returns.
Meanwhile, Ben Gibson has agreed a new five-year contract with the club.
The England Under-21 international signed his new deal yesterday afternoon with the club he has supported since childhood.