We take a look at some of the memorable 'panic buys' the Teessiders have made over the last 20 years – from deadline day deals to hyped-up arrivals. Scroll down and flick through our picture gallery to see the full list of players who have since left the club:
5. Kris Boyd
Technically Boro didn't pay a transfer fee for Boyd after the striker turned down a new deal at Rangers. Boro still spesignificant money on the player's wages though - a move which didn't come off. Photo: Michael Regan
6. Afonso Alves
Signed for a record fee and with a big reputation, the Brazilian frontman endued a season to forget in his only full campaign on Teesside. Alves netted just four Premier League goals in the 2008/09 season as Boro were relegated from the top flight. Photo: IAN KINGTON
7. Mido
The Egyptian didn't come with the same reputation as Alves but still cost Boro around £6million after signing from Tottenham Hotspur. Like Alves, Mido netted just four league goals in the 2008/09 season which ended in relegation. Photo: Julian Finney
8. Mohamed Shawky
A two-time Africa Cup of Nations winner with Egypt, the central midfielder struggled to nail down a regular starting spot at Boro. Injuries were a factor as Shawky left the Riverside with just 22 appearances to his name following Premier League relegation. Photo: AFP