Reports late last night and this morning stated that Pablo Mastroeni, an ex-team mate of Karanka, would become Aitor's new assistant following the departure of Craig Hignett earlier in the week.
However this morning Aitor told mfc.co.uk "Pablo is head coach of Colorado Rapids and is not coming here to work with us.
"He is an old team mate and a friend. We were talking about a player we have been looking at and from that conversation it was agreed that Pablo could come over to watch the coaching methods in this country for a week to develop his own education, no more than that.
"When the Colorado Rapids website said Pablo was coming to work with me, everyone over here jumped to conclusions that he would be coming to work as Higgy's replacement.
"That is simply not the case."
Boro's Head Coach added: "There is nothing to report regarding Higgy's replacement. There is no timescale. It could be tomorrow, it could be next week, it could be next month."