And Guardiola indicated he will give the Argentina attacker as much time as possible to prove his fitness.
"Tomorrow [Tuesday] is such a big game and Sergio is here because the doctors said he is able," Guardiola told a news conference.
"Tomorrow we will decide whether to play him or Gabriel Jesus.
"[Fabian] Delph, no. Benjamin Mendy maybe [available to play Liverpool on Sunday] - we have enough days until the game so hopefully.
"The problem is that they still didn't train with us, so hopefully when we return they can train with us."
PEP: We have five finals ahead in the Group Stages. Tomorrow is the first final.— Manchester City (@ManCity) October 1, 2018
Like Vincent said perfectly, it’s a top quality competition, it’s so complicated for all of us and we try to be stable. I think we are making steps forward.
City received a boost with Kevin De Bruyne returning to training earlier than expected on Monday.
However, the Belgium star will not be available to play Hoffenheim and Guardiola is cautious over rushing his playmaker back to action.
"Today was his first training session back with the team so we will see when he's ready to play."
Speaking before Guardiola at Monday's news conference, City captain Vincent Kompany hailed the returning De Bruyne.
"It's difficult to quantify how much of a loss he has been," Kompany said of his compatriot. "He is one of the best midfielders, we get more goals and assists with him.
"Luckily we have players to fill the gap. He has a huge presence and you don't find it anywhere else in football."