The Football Association is investigating a laser being shone at Manchester United’s Wayne Rooney during the League Cup defeat by Middlesbrough.
Television footage showed a green light appearing on Rooney’s face as he prepared to take his penalty.
The striker’s effort was saved by Boro goalkeeper Tomas Mejias and United were beaten 3-1 in the shoot-out after the game finished 0-0 following extra-time.
The FA said it is aware of reports of the incident and is looking into it.
The penalties were taken at the end of Old Trafford housing the away supporters.