"Igor has been brilliant since he came into central defence," said Riise. "He hasn't played many games in the time I've been here but he has never been down. He has always been happy in training. Now he's in the team he's doing well.
"He has surprised me because he has kept his head up for so long despite not having played much and he always wants to learn. Igor is quick, very strong and good in the air. There aren't many strikers who can get past him.
"For Igor to keep his head up for so long when he hasn't been playing is real professionalism."