Abraham has found himself on the outer under new manager Thomas Tuchel.
He told the Evening Standard: "I would imagine it is down to his ankle not being right.
"Managers nowadays will rotate, even on the bench, and I think that has been happening at Chelsea. I would imagine it is down to that ankle, he has to get that right.
"Young players have to come through injury, that is part of being a professional footballer and part of your education. How do you cope when you are out? Does it make you more hungry? Or does it make you more fragile? Are you worried about getting your form back? Callum Hudson-Odoi has had a problem with his Achilles. He would have had doubts.
"So there are a lot of things you have to overcome as a young player coming into football. You are very lucky if you go through your career without any injuries or doubts to overcome. I get a feeling that is where he is at, he is a bit worried about that and that is why it is not working out for him at the moment."