The transfer mill is churning once again, with Manchester United believed to be lining up a move for Pharrel Nnamdi Collins, the defender from Frankfurt. Sources close to the club suggest they are exploring options to reinforce their squad ahead of the run-in. Manchester United are still pushing to finalise terms. However, Chelsea, Liverpool and Arsenal are still watching closely and may return with offers of their own. So far in this season, Manchester United are conceding 1.67 goals a game (15 in 9), more than they'd like compared to the Premier League standard. The hope is Pharrel Nnamdi Collins adds a bit of steel and helps make them tougher to break down. Reports suggest Manchester United are monitoring Dennis Seimen, Estevao and Folarin Balogun whereas Frankfurt have not been associated with other players at this stage. Stay tuned for more details as the story develops. Need more Manchester United transfer rumours? Follow @PlayerSwitchCom on Twitter for news and updates as they happen.