Manchester United defender Marcos Rojo admits he's not a good spectator.

He suffered a knock in training which ruled him out of the 3-0 win over bitter rivals Liverpool.

Rojo, who is in line to make his second comeback in the Boxing Day clash with Newcastle, admits his spells on the sidelines have been frustrating.

He said: "When you're not on the pitch, you do suffer a bit more during the game.

"You want to be able to go out there and help your team-mates, but all you can do is wish them well."