Lee first arrived Vietnam in 2017 when he became his former teammate Park Hang-seo's assistant manager, ushering in a period of success for Vietnamese football.

Lee and his compatriot Park went on to gain plenty of success, with Vietnam finishing second at the AFC U23 Championship 2018, reaching the semi-finals of the 2018 Asian Games, winning the 2018 AFF Suzuki Cup, and reaching the quarter-finals of the 2019 Asian Cup.

Thanks to his significant contributions, the Vietnamese Government awarded Lee a Labour Order, Third Class, in 2018. 

However, his contract with the Vietnam Football Federation (VFF) ended on January 31.

The Fair Play awards are given by Phap Luat Thanh Pho Ho Chi Minh (Ho Chi Minh City Law Newspaper) to honour the noble actions of players, referees, and supporters.