"I played with him at Manchester United for two years and he couldn't speak English when he arrived but neither could I!" said Carroll.
"He was very hard working when he came from Sporting Lisbon and I learned from him, with the shots he put against me in training.
"He has developed himself since as an all-round player and we know what he can do.
"He is physically so much harder and worked a lot in the gym and looked after himself on and off the pitch. He's a much stronger player in the last five years, you can see that."