Manchester United boss Louis van Gaal has revealed that he selected Anthony Martial in his matchday squad to face Liverpool due to the "very good impression" made by the youngster.

The 19-year-old signed from Monaco earlier this month in a move that was widely ridiculed because of the lofty £36m price tag.

Martial made an instant impact in front of his home supporters, though, after coming off the bench to score United's third goal in the 3-1 win over Liverpool on Saturday evening.

Speaking to Sky Sports News, Van Gaal was delighted with the former Monaco man's debut performance, but has urged some caution.

"We have scouted him and we wanted him because he's the best in his age, he needs time," the Dutchman said. "He's been with us for three days, that is too short to judge his personality, but he made a very good impression in first three days, that's why I selected him to be on the bench."

United's win over Liverpool lifts them up to second place in the Premier League table.