It's a bummer he hasn't worked out, but I wouldn't slate him. The move to us might have come too early for him. I never really saw the talent -- he seems tidy at times but also has a lot of difficulty with positioning and plays timidly -- but it was a low-risk gamble and he's been professional to my knowledge. Things can of course change, but I would be fine with him seeking opportunities elsewhere. Hopefully we can get a fee that's not too much lower than what we paid!
I think it's worth it for us to take the odd chance on younger + cheaper players, and this is one of those cases of too big, too soon. I can't blame him for that and hopefully he can find somewhere to continue growing.
He hasn't taken off like we'd hope, that's for sure. But I do see more talent with him than I ever did with Lokonga. While Vieira can get bullied out of games, I do see good flashes when he comes on as a sub and doesn't overthink things. (He's more aggressive and progressive in those instances, especially when we're losing or tied with a lesser side.) To be honest, I think Vieira is also a level below what we want from our backups now (given our ambition and investments), but I see him as more likely to come good. At least he's probably retained more of his value than Sambi if we were to sell him -- though I would be surprised if we did this window.
I'm on the fence about him. There are flashes of brilliance but from what I have seen I'm not quite convinced he has the ability to be anything other than a backup.