Boro brought in goalkeeper Jordan Archer, Darnell Fisher, Yannick Bolasie, Nathaniel Mendez-Laing and Neeskens Kebano to bolster their squad as they push for a play-off place in the Championship.
The Teessiders have also welcomed back defender Grant Hall and striker Ashley Fletcher from injury – so who will start when everyone is fit and available?
Obviously there will be more injury setbacks before the end of the campaign, and Warnock will choose to alter his side and formation depending on the identity of the opposition.
Still, we’ve put together what we think could be Boro’s strongest starting XI, and substitutes bench, when everyone is fit.
Scroll down and flick through the pages of our picture gallery to see if you agree:
5. LB: Marc Bola
Boro's first-choice option at left-back. Has looked assured defensively and also provided an attacking outlet this season. Photo: Alex Burstow
6. CM: Jonny Howson
Is enjoying some of the best form of his career after returning to his natural centre-midfield role. Photo: George Wood
7. CM: George Saville
Has started nearly every league game under Warnock when he's fit. The midfielder has excelled in a box-to-box midfield role which allows him to contribute in both boxes. Photo: Getty Images
8. RW: Neeskens Kebano
Can operate in multiple positions including out wide or in the No 10 position and will give Boro more attacking firepower for the second half of the campaign after signing on loan from Fulham. Photo: Getty Images