Karanka was sacked by Boro chairman Steve Gibson in March and replaced by his assistant Steve Agnew for the remainder of the Premier League season.
During the January transfer window, Garry Monk had a plan to land the 26-year-old midfielder and to strengthen this part of his team.
Monk says the "clarity" of the set-up at Middlesbrough appealed to him and believes they're equipped to win promotion straight back to the Premier League.
Ex-Swansea boss Monk, 38, added: "Steve Gibson was integral to my decision to come here". The club are also quite far down the line in terms of organisation and the determination with what they wanted to do and that ties in with myself and having those ideas and they aligned really well. "I've got an opportunity to show myself against and with the best players from our country".
"Promotion has to be the ambition, and that's the kind of challenge that you want". But things changed after Radrizzani assumed full control of the club from a fellow shareholder, Massimo Cellino.
"I left Leeds and then I went away for a few weeks on a family holiday and obviously you weigh up what your options are but to be honest with you, as soon as I spoke to Middlesbrough the situation was clear". It didn't suit me.
While clarity and leadership on the national political stage remains a bit of a moot point, Monk and the Boro hierarchy have clearly found a meeting of minds in the footballing realm.