Mbappe picked up a thigh injury in the first leg at the Parc des Princes and has been struggling since. He returned to individual training at the Etihad on Monday night ater being rested for PSG's Ligue 1 clash with Lens over the weekend, and Pochettino claimed the 22-year-old could start on Tuesday.
"We still have to assess the situation with Kylian," the PSG boss said. "Today he's going to train on his own and we will see if he can do it with the group at the end. We have one day left. We still haven't made a decision."
City boss Pep Guardiola is certain the 22-year-old will make it: "He's going to play," he said. "And I'm looking forward to him playing."
However, Pochettino is unfazed by the task that lie ahead, and said: "I think "Houston, we have a problem" if we need to motivate our players or Manchester City need to motivate their players!
"I saw Pep in his press conference say "I'm more relaxed than ever". In my position it's the same, I am so relaxed, I'm enjoying (it) because it's difficult to arrive at this stage. I am relaxed like two years ago, knowing we are going to face a very good team but we have good quality players too, we're a very good team too. It's going to be a battle."