United stretched their unbeaten run to eight matches on Boxing Day with a comfortable 3-1 win over Newcastle.
Wayne Rooney scored twice and set up Robin van Persie for the final goal in the convincing victory at Old Trafford.
Van Gaal was delighted with his team's performance, but he was not so happy with the fact that he has been given less than 48 hours to prepare for Sunday's lunch time kick-off in north London.
"With FIFA and UEFA, it's forbidden to play within 48 hours
In England, it's okay," the United manager said.
"I cannot prepare my team like I have to prepare
We have unit meetings, and team meetings, we have training 11 against 11, and assimilating opponents
We cannot do that now."
Adnan Januzaj and Marouane Fellaini are doubtful for the Spurs game after missing Friday's win due to a virus.
Luke Shaw took part in a post-match training session at Old Trafford and could be involved, while Van Gaal said Marcos Rojo is "responding very well" to treatment on his thigh injury.
Daley Blind remains two weeks away from full fitness and United look set to be without British record signing Angel di Maria, who suffered an injury in training on Christmas Eve.
"The pelvis is not in a right relationship with his leg," the former Bayern Munich coach said.
"I don't think (it's serious), but I am not a doctor."
At least United head to the capital full of confidence after outclassing a Newcastle team who admittedly made life easy for their hosts because of some sloppy defending.
Rooney dominated the game, scoring a brace following two well-timed runs from midfield
His long, lofted pass to Van Persie for the third was something United great Paul Scholes would have been proud of.
"It's a role that I've played many times and I know I can play," Rooney said when asked about playing in the number 10 position behind Van Persie and Radamel Falcao
"The manager has given me even more licence to get forward and get into the box from that role.
"As Paul (Scholes) did many times over his career, he could see the ball when it was wide and see the space and run into it - I did that (against Newcastle) with my two goals
It's nice to win, nice to score goals and I'm delighted with the performance."
The Magpies only found the net in the 87th minute when Papiss Cisse scored a penalty following Phil Jones' foul on Jack Colback.
It could have been a different story had referee Michael Jones awarded the away side a spot-kick in the first half when Juan Mata clipped Yoan Gouffran's heels.
Newcastle boss Alan Pardew was unhappy with the decision.
"The referee has got a bad call very wrong," said Pardew, who takes his team to Everton on Sunday.
"I think that was a penalty
I think Mata's run across the back of a player who is going to head the ball across goal
That's a goalscoring opportunity
It was clumsy and that was a penalty."
Source : PA
Source: PA