Manchester United are reportedly keeping an eye on Bolton's Gary Cahill ahead of his potential switch to Chelsea.

Cahill, who has been linked with a move since the summer, is understood to be struggling to agree personal terms with the London club after Bolton agreed to sell the centre-back for a £7m fee.

Meanwhile, the Manchester outfit are believed to be monitoring the situation after suffering injuries across their back line and losing skipper Nemanja Vidic for the season, according to The Sun.

Sir Alex Ferguson said last month that the club would not look to enter the transfer market unless a long-time target became available.