Louis van Gaal has once again tried to play down expectations surrounding Anthony Martial after he scored his fourth goal in as many matches for Manchester United.

United strolled into the fourth round of the Capital One Cup with a routine 3-0 win over Championship side Ipswich on Wednesday.

Wayne Rooney scored his first goal in domestic competition this season and Andreas Pereira converted a stunning free-kick on his full debut, but it was Martial who stole the headlines once more.

Twenty minutes after his introduction from the bench, the 19-year-old Frenchman latched on to Memphis Depay's knock-down and rolled the ball beyond Ipswich goalkeeper Bartosz Bialkowski to complete the victory in injury time.

Martial has now scored four goals in just 225 minutes for United, but Van Gaal wants to protect his prize asset and resisted the temptation to lavish praise on the £36million forward after the match.

"That is not so difficult (for him to stay grounded) because he is a player who is very modest and he knows he can score because of his fellow players," the United manager said of the most expensive teenager in history.

"We made it two times very easy (for him) because we won the game and then the gaps are existing and then with his speed and his composure he can score.

"He did it also against Liverpool and now again. We are happy but still we have to keep our feet on the ground."

Until Martial came on to the pitch to great acclaim from the home fans inside Old Trafford, it looked like being Pereira's night.

"What is realistic is dependable on the level of the players. I put always the best player in the line-up when he is working for the team"

The Brazilian had impressed greatly on United's pre-season tour but until Wednesday, the talented forward had not got a sniff of first-team action this year.

The 19-year-old reminded Van Gaal of his talents in the best way possible on the hour, dipping a lovely free-kick over the wall into the corner while Bialkowski stood there motionless.

Just as he did with Martial, Van Gaal was wary of lauding the teenager for his efforts and warned him he faces strong competition to earn a regular place in the United team.

"He can play all these positions (across the front)," Van Gaal said.

"And his competitors are (Ashley) Young, (Memphis) Depay, (Juan) Mata, (Ander) Herrera, (Wayne) Rooney, (Marouane) Fellaini and (Jesse) Lingard. What is realistic is dependable on the level of the players. I put always the best player in the line-up when he is working for the team."

After exiting the Capital One Cup at the first hurdle last term to MK Dons, Van Gaal was pleased to advance to the fourth round, where United will face Middlesbrough at Old Trafford.

"It is the top club in the Championship," the United manager said of United's next opponents in the competition. It shall not be easy. Also this game was not easy. I am happy with the result and the draw because we are playing at home."

Van Gaal's opposite number Mick McCarthy, who made 11 changes for the match, was happy with his players despite the result

"Manchester United deserved to win," the Ipswich manager said.

"But I am delighted with my players. I could have put any team out against that team and probably still would have been beaten."