The 23-year-old spent the second half of last season on loan at the Riverside, having moved to the Championship outfit in January.
Roberts is set to return to the Championship team for a second loan spell for the remainder of the current season with a deal set to be penned today.
Boro boss Neil Warnock is looking to bring in up to four players on loan to bolster his squad before the current transfer window slams shut and has been keen on bringing Roberts back.
The Manchester City winger proved to be a useful addition for Boro in the last campaign, impressing before his injury and returning to play a key role in the successful battle for their Championship survival.
He returned to Manchester at the end of last season but is down Pep Guardiola’s pecking order at the Etihad with the Spaniard having an embarrassment of riches in the attacking department at his disposal.
Roberts played eleven times for Middlesbrough in all competitions during his first stint with the club.
The Englishman has also been shipped off on loan stints at Celtic, Norwich City and Girona since arriving at the Etihad in the summer of 2015.
