Louis van Gaal described the second half of Manchester United's goalless draw at Tottenham as "a struggle for life" after outlining his frustrations with a fixture schedule which demanded two Premier League matches in fewer than 48 hours.

The visitors, who had not lost at White Hart Lane since May 2001, swept Newcastle aside in 53 minutes in the 3-1 win on Boxing Day.

Had it not been for Tottenham goalkeeper Hugo Lloris, United would have been out of sight at the interval after what Van Gaal believes was the best first-half showing by his team this term.

Lloris saved twice from Radamel Falcao and denied Robin van Persie and Ashley Young and was complimented by opposite number David de Gea as the teams left the field at half-time.

The one time Lloris was beaten Juan Mata's deflected free-kick hit the post and Vlad Chiriches cleared the rebound off the line ahead of Van Persie.

"When you play your best first half of the season as Manchester United, at White Hart Lane, a top six club of the Premier League and you play like that, create six to eight chances, open chances, you have to finish that," Van Gaal said.

"If you don't reward yourselves then, normally the opponent wins.

"You could see also the difference in the second half – it was not football any more, it was a struggle for life. Tottenham won the second balls and that's why they were more dominating than Manchester in the second half.

"You need also a little fortune. Tottenham could score also in the second half. I'm happy that they didn't."

Van Gaal believes football's authorities are culpable for intensity of the contest dwindling.

"It's scientifically proven that the body cannot recover within 48 hours," he said.

"When you, as an FA, allow that to play matches, you see what it's like.

"The second half was much different from the first half. And not only for Manchester United, also for Tottenham Hotspur.

"I think Tottenham Hotspur can play much better than today. Also my team could've played in the second half much better. You cannot do that."

United named an unchanged starting XI for the first time since November 2012, in 85 Premier League games, but it was out of necessity, according to Van Gaal.

The Dutchman made three defensive substitutions, but insisted Luke Shaw and Chris Smalling could not have played from the start having recently returned from injury.

Van Gaal added: "You cannot play 90 minutes. Maybe you can play 20 minutes. I take the risk already with these kind of players, putting them on the bench. That's why I could not change."

United have won just twice in nine matches away from home this term, with the wins at Arsenal and Southampton followed by draws at Aston Villa and now Spurs.

But Van Gaal maintains the title is a realistic prospect as his side are improving all the time.

He added: "I said this also in the dressing room: when you cannot win such a type of matches when you are the better team against Aston Villa and also now, it's very difficult to be the champion at the end of the season.

"Still (I think we can win). We are improving every week. I was very happy with the first half."

Asked if United will be improved in 2015 after a fraught last 12 months, Van Gaal added: "Of course. Of course. Of course, we shall be better. So, watch."

Tottenham boss Mauricio Pochettino felt his side were worthy of a draw after Lloris' heroics.

Pochettino said: "I think it's a fair result. Lloris is one of the best goalkeepers in the world. It's not new for me. We know the quality from Hugo."

Pochettino felt Spurs might have had a penalty in the second half following Wayne Rooney's grappling on Harry Kane at a corner.

"Maybe it was a penalty, from seeing the TV now," Pochettino said.

"But from my vision during the game it was difficult to identify if it was a penalty or not."

Mobile app users, watch the video highlights here.