After watching the show about Lee, I would say to him, go to Vietnam. I think he peaked in 2014-15 and has been slowly sliding downhill since. Next year he turns 32 and this is a young man's game. Go to Vietnam, where they want to treat you like a rock star, a la David Beckham. There you will be set for life and thank you very much for all you did for the Revs. The Revs aren't going anywhere in the next couple of years, so why put up with the frustrations.
Nguyen is from Dallas. If he wants to leave, I'd trade him to Dallas. Dallas has a highly rated 21 yr old left-back out on loan, Anibal Chala. I'd swap Nguyen for Chala + a chunk of cash. Mauro Diaz is injury-prone, and they could play with them both in a 4-3-2-1 or with Nguyen on the left wing.