Villas-Boas said: "It's a long time since we worked together. Steve has taken his steps very wisely and I'm happy he has achieved his ambition of becoming a manager.
"I respect him a lot because he took those steps sensibly.
"He got the opportunity to be in the Premier League in a club as well organised as West Brom where he can build something extremely good.
"It's a great chance for him so I'm happy. I congratulate him on getting the job."