Riise's two appearances have resulted in a 3-2 defeat to Peterborough followed by a 1-0 reverse at Leeds.
"I played for the first time against Peterborough - a game we should have won. That was a confusing game because the result did not reflect the performance," the 28 year old told the club's website.
"We should have got more points from the last couple of games. I think we did enough to get points from both of them. Alright, we were bad in the first half at Leeds but credit to the lads for improving so much after the break.
"We've created lots of chances in both those games - that's a positive we can take. But what we have to make sure we do now is make the most of the chances that come our way."