Rafael again shone at right-back in victory over QPR yesterday.
"I think we've played the same back four over the last few weeks and young Rafa had a really good game [at Blackburn]," said the boss.
"He's doing well. He was always a rash, young boy and his enthusiasm was overwhelming at times but he's settled down quite well and is quite calm in his game now. So, by doing that, he's brought his game to a really good pitch at the moment.
"He's playing really well and combined well with Valencia. There's a good understanding there."