Newly promoted J1 League team Yokohama on Sunday announced they had signed Phuong on a two-year deal but did not disclose his salary.
On Facebook, Phuong wrote: "I want to thank the fans for supporting me and HAGL for making me who I am today. I will always appreciate my time at the club."
Phuong’s contract with HAGL expired in early December and he decided not to extend and instead joined Yokohama as a free agent.
He will not play for Vietnam in the 2022 AFF Cup since he will be busy making arrangements for settling down in Japan.
"This is a new chapter in my career," he wrote.
"I’m happy to join Yokohama with a new environment, teammates and challenges awaiting. I’m ready to contribute to the success of the team. I will try my best at Yokohama."
Yokohama finished second in the J2 League last season and got promoted. They have eight foreign players in their squad, including six Brazilians and a German.
Previously another HAGL player, Nguyen Tuan Anh, went to Yokohama on loan in 2016, but did not get a game.
Phuong is the third Southeast Asian player in the J1 League after Thailand’s Chanathip Songkrasin (Kawasaki Frontale) and Supachok Sarachat (Consadole Sapporo).