"Glen has been really good for us since the very first day and also for England. You can see his offensive mentality and his crossing is really good," said the boss.
"I was surprised to see some criticism the other day. He is a very good player. He can improve and he knows this - he is someone who is keen to learn.
"He is so good attacking that sometimes it is difficult for the defenders of the other team to stop him than it is for him to be worried about the defence.
"He can improve in defence, but he is a decent defender and very good at attacking. He has a very good balance and his understanding of the game is good."