The Parisians hold a 3-2 lead in the tie after a famous victory at the Allianz Arena last week.
But Pochettino isn't letting his players get complacent for the return leg on Tuesday.
"It was already hard to keep the ball against Barcelona already, it doesn't matter who is playing. It's a question of collective attitude," Pochettino said.
"It's a challenge for tomorrow, being able to keep the ball and hurt the opposition.
"The Barca game is behind us and the Bayern game is another story. There will be moments when we will struggle and it's in these moments that we will need to show solidarity and solidity."
Pochettino admitted he was unsure if star defender Marquinhos would play after injuring his adductor muscle injury in the first leg.
"I don't know yet if he will be playing," said Pochettino.
"We will see how he feels tomorrow and he could be in the squad but I don't think he will be able to start. So maybe he'll be on the bench."