"Craig will strengthen this team because he is a quality player," said Hughes.
"A lot of people's judgment of him is clouded by past misdemeanours but there is no doubt what he can bring to us.
"His pace and running off the ball is something we have not really had and he can help open up defences for us.
"Craig could have stayed at West Ham and been a top player for them for five years. He could have been up there with Paolo Di Canio as one of their very best.
"But he wants to be remembered for football and he wants to make his mark on the game. He wants to play at the top level and wants to be part of what we are trying to achieve here."