Birmingham officially acquired Ashley Young for 8 million pounds sterling and signed a four-and-a-half-year contract with him. The total redemption amount could later increase to 9.65 million, depending on the conditions of the deal.
A.Young is expected to earn around 30 thousand pounds per week, and his debut should take place on January 31 against Newcastle.
"He has great potential and I believe he will prove it," said Aston Villa manager Martin O'Neill. "Ashley is a very talented player."
"I believed he would come to my team after giving verbal consent, but nothing can be guaranteed until the player puts his signature on the contract. I think he is a great player, capable of playing on both wings and in the middle. I am very happy with this acquisition," said the coach.
Watford head coach Aidy Boothroyd believes that A.Young can reach a new level under M.O'Neill's guidance: "I think Ashley can rise even further because of his mental abilities and the coach he will play with. Everyone who gets into a team led by O'Neill is very happy."
"A.Young is worth those millions. He will cope with the tasks that await him because he is a very strong guy. He has a great future ahead," said the former player's coach.
The 21-year-old England youth international joined the main Watford team in 2003 and scored 22 goals in 83 matches.
This is already the second acquisition for Aston Villa this week - in exchange, Birmingham received Norwegian John Carew from Lyon, giving away Czech Milan Baroš in return.