Celtic reportedly wanted Johnson in the summer of 2017.
Marvin Johnson has made seven Championship appearances for Sheffield United since arriving on loan from Tony Pulis's Boro.
Johnson has failed to break into Boro's side of late.
Sheffield United are reportedly in talks to sign Middlesbrough’s Marvin Johnson on loan.
Aston Villa are reportedly set to beat Championship rivals Middlesbrough to the signing of Everton winger Yannick Bolasie. What does this mean for Marvin Johnson?
Aston Villa and Middlesbrough are said to have eyes on the same player, which could impact Sheffield United's own transfer plans.
Middlesbrough pair Ashley Fletcher and Marvin Johnson could be set to depart the Riverside with Hull City reportedly keen
Sheffield United are reportedly keen on Marvin Johnson.
Middlesbrough winger Marvin Johnson helped Tony Pulis's side to victory on penalties against Notts County.
Celtic were linked with Marvin Johnson last summer, and should perhaps consider a fresh move for the 27-year-old