The Japan international moved to Molineux earlier this month on a three-and-a-half-year deal from the Swiss Super League side and has spent the past few weeks training and learning under Bruno Lage and the Wolves first-team squad at Compton Park.
Wolves' technical director, Scott Sellars, said: “He's integrated into the club very well, he's been training with the first-team and experienced what the levels and the quality of the Premier League is like. During this period, he's shown what a good player he is, but he knows he needs to continue working hard to develop his football.
“Now everything appears to be getting back to normal, and with our squad continuing to get stronger, we believe the best way for Hayao to continue his development is by playing regular football back at Grasshoppers.
“He had a great start to his time in European football during the first half of the season, and we would like him to continue that – especially with the World Cup coming up. We want him to be ready, and having lots of games under his belt will give him the best opportunity to earn a selection for Japan.
“We'll continue to monitor Hayao while he's back at Grasshoppers. We hope everything he's learnt in the last few weeks will really benefit him going forward and look forward to seeing him back here soon."
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!