The 23-year-old joined Wolves last season for a then-club record fee of £13m and was a standout performer for the Midlands outfit, scoring 10 and creating eight more in 36 Championship appearances.
Costa's season came to a premature end at the start of April courtesy of an ankle injury, but the Portugal youth star is now back in training and gearing up for a return to competitive action.
"Yes he's getting closer," Nuno told reporters yesterday. "We have to regard all the problems of Helder comes from last season.
"He didn't have a pre-season, he started working, then surgery, he's in the process of coming now.
"He's not totally free of pain but he's making the right steps to be inside the squad as soon as possible."
Wolves have made an impressive start to the new Championship season, losing just one of their opening seven games to sit fourth in the early standings.