Karanka has recently been appointed the manager of Championship club Forest, who dismissed Mark Warburton as the boss on New Year’s Eve.
The Spaniard had been without a managerial job since since March 2017 following his departure from Middlesbrough.
The former Real Madrid defender was a huge success during his time at the Riverside Stadium, as he guided Boro to the Premier League from the Championship.
Forest are struggling in the Championship at the moment and are unlikely to finish in the top six of the table this season.
Well-known Spanish football journalist Balague, who works for Sky Sports, has suggested on Twitter that Karanka had other offers but chose to take the Forest managerial job.
Karanka ya ocupa el banquillo del único equipo con más copas de Europa que ligas. pic.twitter.com/rt6jPpJP3K— Revista Líbero (@revistalibero) January 11, 2018
Forest will return to action on Saturday evening when they take on Aston Villa at the City Ground in the Championship.