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:
5. Kadeem Harris (Sheffield Wednesday)
Harris, 26, was a free agent after his contract at Cardiff expired. Wednesday were quick to snap him up and the winger has been a key player for the Owls. Photo: Stu Forster
6. Mbwana Samatta (Genk)
It always seemed a long shot Boro would land the Belgian striker who scored 20 league goals for Genk last season. Samatta has continued his fine form this campaign, netting five goals in nine league appearances so far. Photo: JOHAN EYCKENS
7. Ryan Kent (Rangers)
A return to Rangers always seemed the most likely outcome for the winger following his loan spell at Ibrox last season. However, since his permanent switch from Liverpool, Kent has made just one league appearance due to a hamstring injury. Photo: Ian MacNicol
8. Stephen O'Donnell (Kilmarnock)
Reports linking Boro with the Scottish full-back recently resurfaced. O'Donnell, 27, will see his contract expire at the end of the season but he remains a key player for Kilmarnock. Photo: Ian MacNicol