Messi missed PSG's two games with Metz and Montepellier after sustaining a knock in a 2-1 win over Lyon.
With PSG hosting Pep Guardiola's Manchester City, Pochettino has disclosed the former Barcelona forward could be included in the matchday squad.
"We will confirm the starting 11 tomorrow (Tuesday),” coach Mauricio Pochettino told a news conference when asked about Messi ahead of the Group A clash at the Parc des Princes.
“But I think he will be in the squad tomorrow.
"He did 20 years in Barcelona, it’s normal he felt at home there and here, everything is new for him. He did not arrive a long time ago."
PSG, having shared spoils with Belgian side Club Brugge in their first game, the Parisians will hope to record a first win over the Citizens who will be visiting as table-toppers.
Aside a possible return for Messi Pochettino also confirmed that Marco Verratti would probably be involved after being absence four games with a knee injury.
“He trained well the last few days and we think he will be able to be in the squad. We haven’t decided on the starting 11 but he could be in it,” he said.
Messi has still not scored for his new club after three games.
