The long-serving centre-back was the last key figure of Boro’s 2015/16 promotion-winning side which provided some great memories under Aitor Karanka.
We’ve taken a closer look at what has happened to the squad four years after they reached the Premier League.
Scroll down and flick through the pages of our picture gallery to see the players who made five or more appearances for Boro during the 2015/16 campaign:
1. Dimi Konstantopoulos
Now 41, the Greek shot stopper is assessing his options after a brief spell training with former club Hartlepool last year. Photo: Nigel Roddis
2. Tomas Mejias
Back at Boro following a spell in Cyprus playing for Omonia Nicosia. Third choice at the Riverside behind Aynsley Pears and Dejan Stojanovic. Photo: NIGEL RODDIS
3. Emilio Nsue
After a couple of years at Birmingham, the 30-year-old has moved to Cyprus and is playing for top-flight side Apollon Limassol. Photo: Jan Kruger
4. Tomas Kalas
The Czech defender, 27, signed permanently for Bristol City last summer and, despite some injury setbacks, has been a regular starter when available Photo: Chris Brunskill