Karanka, who is now in charge of Birmingham, provided plenty of great memories for Boro fans during his time at the club – but what has happened to the squad which reached the Premier League under him?
Scroll down and flick through the pages to see the players who made five or more appearances for Boro during the 2015/16 campaign and where they are now:
21. Christian Stuani
The Uruguayan has been in red-hot form for Spanish side Girona since leaving Boro. The forward scored 29 goals in 36 second tier appearances last season but suffered an injury setback this campaign. Photo: Jordan Mansfield
22. Gaston Ramirez
Eventually left Boro for Italian side Sampdoria in 2017. Scored seven goals in 26 appearances in Serie A last season and has played 11 times this campaign. Photo: Michael Regan
23. Kike
Has led the line for La Liga club Eibar since leaving Boro in 2016. Missed a chunk of last season through injury but still made 27 league appearances. Photo: Nigel Roddis
24. David Nugent
Re-signed for former club Preston last summer after a couple of years at Derby. Was in and out of the side for The Lilywhites last season and hasn't been used this campaign. Photo: Stephen Pond