Diego Costa won't need an operation to repair his ongoing hamstring issue.
"To work as he does in the season, in prevention to make the muscle stronger, but at the same time elastic and flexible [is the best approach]," Jose Mourinho told a news conference. "Recover well with no big accumulation of fatigue -- this is what we do.
"We don't believe in operations. Our medical department and myself, we believe an operation is the last resort for every injury, so we try and be conservative, to train and recover and try and compensate the problems. I don't believe we'll ever go in the surgery direction."
Mourinho said that Costa has been working hard during the international break to improve his fitness