The Citizens sold Jesus to Arsenal the summer before they went on to lift the trophy.
Arsenal and Jesus take on Bayern Munich in the quarter finals of the competition this term.
Jesus said of his fitness isuses: I don't remember the last day I played football without pain so I cannot complain.
I'm just trying to recover good to be ready. I personally don't normally want to talk about my fitness. After the World Cup I had that injury in my knee and I recovered so well, but had a setback after the pre-season.
I played in like three 90 minute games in a row and again a pain in the knee. Then after training, I had a kick in the knee. I'm just trying to get fit and help Arsenal as soon as I can. Unfortunately, I've been having some problems and people don't always see that. But mentally, I try to be strong in my mind. That's it."