Forrest keeping him out the team is a simple one to answer, down to work rate. Roberts tracking back is pretty poor but he is improving on that front...........Forrest on the other hand puts in a shift, lacks the quality but his work rate is excellent.
I think you are right, Navas was on a different level to Roberts but right here and now he is not, living off his past IMO and his only asset is his pace which is also his biggest downfall as he relies on this alone to impact on games and in the EPL the players are similar in terms of pace so he has no advantage.
I have actually seen a fair bit of Navas, well any time I'm at my brother in law he watches that shit down south and is also a big city fan since he was a young lad..........he does not rate Navas at all and views him in a similar fashion to me, and he likes City !!!
Be interested to hear what LB or Norn thinks of his ability seeing as they support the big team in Manchester.
I did mean Iheanacho, think its pronounced the way I had written it although not sure tbh.
Anyway as you say its all down to opinon, I think not only is Roberts good enough for that City squad but also better than in the team fighting for the same positon.