You're kidding yourself thinking Koeman didn't play him because he doesn't rate him.
It's pure ego.
If he thinks Arouna Kone is good enough then Niasse is too.
Why would he do that?
Martinez bought a lot of shite and they all got game time except this guy. The fact that the man who bought him never played him either says to me it's simply a case of him not being up to scratch.
Anyway, regardless of the reasons for freezing him out, it's still not a climbdown. He was in the squad last season and didn't play. He's in the squad this season and won't play. We had inadequate striking options last season and he didn't play. We still have inadequate striking options and he won't play