The Argentine was not happy with the way in which Spurs lost at Old Trafford today.
It was a performance however from Tottenham that certainly deserved more.
They were the better team throughout the game but lacked that pace and movement up front to take advantage of their domination.
After the game, Spurs boss Pochettino was not happy with the mistakes that led to the goal and admitted that more signings needed to be made at White Hart Lane.
"Today we were unlucky. It was very frustrating and disappointing in the dressing room.
“In the first 20 minutes we dominated the game and created a chance. After that mistake we conceded a goal.
"I think we created more chances and deserved more than to lose 1-0.
"I think we played well and a high level. But it's true that when you make a mistake when you have the player in front of you like (Wayne) Rooney, like (Memphis) Depay, like (Ashley) Young then they will get a chance and score.
"Yes, this is very clear. We need to add more players.”
The goal conceded from Spurs was poor. Nabil Bentaleb gave the ball away, not for the only time in the game, and then Walker, who did well to rush back into position, scuffed his rash challenge on Wayne Rooney beyond Michel Vorm in his own net.
Tottenham certainly looked like they needed new players. They lacked pace in attack, both on the wings and up front. Then there was the performance of Bentaleb and Eric Dier playing out of position in the holding midfield role.
These are areas that must be addressed by Pochettino if they are to sustain a challenge for the Champions League this campaign.