Preston North End manager Simon Grayson labelled each of Manchester United's goals "slightly contentious" following his side's 3-1 FA Cup fifth round defeat to the Premier League club.

United moved into the quarter-finals of the FA Cup with their victory at Deepdale Stadium; coming from behind after Scott Laird's opener with goals from Ander Herrera, Marouane Fellaini and Wayne Rooney.

The 45-year-old manager was particularly frustrated with Rooney's penalty, claiming Preston goalkeeper Thorsten Stuckmann did not even touch the United attacker before he went down in the box.

Grayson argued Rooney could have been judged offside in the lead-up to Herrera's goal, while he claimed Fellaini fouled a Preston defender before giving United the advantage.

"All three goals were slightly contentious," Grayson said after the match. "I've seen them all and on another day, we could have had the decisions go our way.