"He has returned to about the level he was at before this trouble occurred," Kyodo news agency quoted Japan head coach Park Joo Bong as saying.
"Our big goal is the (2020) Tokyo Olympics."
Momota became the first Japanese to win a men's singles world championship medal when he claimed bronze at Jakarta in 2015 and also won the Super Series Masters Final that year.
His career stumbled, however, when he was banned from the national team in April, 2016, for visiting an illegal casino and missed last year's Rio Games.
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The 23-year-old only returned to international competition in July at the Canada Open and has been restricted to playing in lower-level tournaments.
Badminton power Japan claimed a gold and a bronze at the Rio Games to finish second on the medals table behind China.
(Writing by Ian Ransom; Editing by Greg Stutchbury)
