John Obi Mikel is expected to complete his move to Boro, paving the way for a Boro outgoing.
Reports suggest Middlesbrough FC have held talks with representatives of the 20-year-old Sunderland forward.
The two-time Premier League winning midfielder was rumoured to have been at Rockliffe Park today.
Reports coming from various media outlets have claimed that Middlesbrough FC look set to bolster their attacking options by going for the Portuguese international.
The 34-year-old English midfielder's future at Middlesbrough FC looks uncertain due to a clause in his contract.
Speaking in the build up to the game, Middlesbrough manager Tony Pulis stated that his team have no fresh injury concerns ahead of the Millwall clash.
Middlesbrough hope that the lack of playing time under Claudio Ranieri could force the midfielder to move.
The 32-year-old striker is currently plying for La Liga side Girona, having scored 12 league goals already this season.
The 25-year-old goalkeeper, who was on loan at Accrington Stanley prior to his move, made a permanent move to Preston last week.
Reports suggest Middlesbrough FC are eying up a move for the 22-year-old Dutch defender.