We could all see Gordon was playing within himself - why then reward him with being our pen taker? Nick's pen was one of the best I've seen - ok he missed one in a knock out - but whose to say his numbers couldn't have been up there. Those goals would have helped take some pressure of him as well.
Let's not delude ourselves that if he had stayed we could have kicked on this season. Speaking of Isak I seem to remember around this time Ornstein saying “But for now, he’s definitely there to stay.”