Alexis Sanchez could be forced out of Manchester United's FA Cup tie with Chelsea due to a freak injury.

The Daily Mail says Sanchez was injured in a freak incident during Manchester United's defeat by Paris Saint-Germain - colliding with a linesman while he was warming up.

Sanchez was preparing to come on for Lingard, who had strained his left hamstring towards the end of the first half in the 2-0 Champions League defeat.

However, the United substitute became distracted by the match action as he jogged along the touchline and ran straight into Italian linesman Fabiano Preti.

The collision floored Sanchez who recovered sufficiently to replace Lingard moments before half-time, but he informed United's coaching staff that he had suffered a leg injury above the knee.

The decision was taken to keep him out on the pitch to stop his leg from stiffening up and Sanchez spent the interval warming up in a training top.