Byrne told the club's official website: "He seems like a really good lad. He's not quiet, so I think he'll fit in quite well here.
"From what we've seen from him he has some classy touches.
"Being brought up through the Arsenal Academy, I'm sure he has plenty of quality.
"As a way of breaking the ice and settling into the squad, Henri had to get up and sing a song to us. He put in a few dance moves too and he wasn't shy at all - most Southerners aren't though."