The Spanish champions took the lead after just 95 seconds in London when Philippe Coutinho fired home from Jordi Alba’s cut back.
Spurs were two behind when Ivan Rakitic scored a stunning long-range strike.
The home side got back into it through Erik Lamela and Harry Kane but Lionel Messi was in inspired form and his second half brace ensured Barcelona ran out 4-2 winners.
But Pochettino was left ruing the fact that his gameplan was out the window within two minutes of the start of the match at Wembley.
“I think if you watch football you understand from the changing room we start the game 1-0 down,” Pochettino told Sky Sports.
“We are a team that needed to win and to concede [so early] the plan was destroyed. It’s difficult to assess the first half because it was difficult for the team to restart and to feel confident.
“When you start a game at this level against Barcelona you cannot concede these types of chances.
Despite the defeat Pochettino was proud of his players and said his squad were ‘heroes’ for battling back against Barcelona.
“To play against Barcelona, when you concede after one minute, I think our players are heroes,’ said Pochettino.
“To chase the game against Messi, Suarez, Coutinho, to be competitive in the second half [they are heroes].
“If Moura scores the third goal we talk about heroes and the manager is the best in the world.