Boro made four new signings during the window, as goalkeeper Tomas Mejias, Marcus Browne, Marc Bola and Anfernee Dijksteel all signed for the club. We take a closer look at some of the players who got away and how they’ve fared since. Scroll down and flick through our gallery to find out:
9. Luca Connell (Celtic)
The teenager's heart always seemed set on a move to SPL giants Celtic who signed the 18-year-old midfielder from Bolton. He is one for the future, though, and is yet to feature in the league this season. Photo: Harry Trump
10. Michael Frey (1.FC Nuremberg)
Whether the reports were genuine or just old rumours resurfacing, Boro were once again linked with the Swiss striker who signed for Bundesliga 2 side 1.FC Nuremberg on loan from Fenerbahce. Frey has played six league games this season, scoring two goals and providing two assists. Photo: BULENT KILIC
11. Dru Yearwood (Brentford)
Boro were reportedly keeping an eye on the 19-year-old who instead signed for Brentford. He has rarely featured for the Bees since the move though. Photo: Pete Norton
12. Grady Diangana (West Brom)
Since his loan move from West Ham, Diangana has made a big impression at the Hawthorns and is West Brom's joint top scorer with four league goals. Photo: Gareth Copley