The Boro boss is still hopeful the club can sign one or two more players before the end of the transfer window but has admitted there will be financial restrictions.
We’ve picked out nine Premier League players who could be available on loan before the end of the window – scroll down and flick through the pages to see the full list:
1. Jake Clarke-Salter (Chelsea)
Boro still appear short at centre-back, especially following an injury to Grant Hall. It doesn't look like Clarke-Salter will break into Chelsea's first team any time soon, despite having two years left on his contract at Stamford Bridge. The defender, 22, spent last season on loan at Birmingham where he played regularly and impressed in the second half of the campaign. Photo: Alex Pantling
2. Filip Benkovic (Leicester)
A player who was on Boro's radar in January but signed for Bristol City instead. The 23-year-old centre-back hasn't features for Leicester first team this season and looks set for a move away. Photo: Harry Trump
3. Patrick Roberts (Manchester City)
Warnock hinted a few weeks ago that a deal to bring Roberts back to the Riverside is unlikely. The Boro boss is a big fan of the playmaker though and feels his side need another creative midfielder. Photo: Getty Images
4. Oskar Buur (Wolves)
The 22-year-old was linked with Boro this week and has been regular in Nuno Espirito Santo's Wolves squads. Boro do appear to lack competition for places at right-back where Djed Spence seems the only natural option. Photo: David Rogers