The weird thing is that the Jets aren’t a good run defense so you take out your most effective runner in Fields…and Jets pass defense is like near the top…so was this the right week to sub in Wilson?
My guess is Tomlin doesn't care about right time or he'd have stuck Wilson in last week. He's also pretty much out of time if he wants to give Wilson a decent look after being hyper-cautious about the injury.
But I also think people are overegging what Fields means for the run game. Sure he's been the most effective runner but he still hasn't made it work overall. What is needed to make it work lies outside the runners - better OL, better scheme, more dangerous pass-run balance - because they'll succeed if they get space and won't if they don't.
And either those things work vs the Jets, at which point the run game could be lethal through Harris/Warren without ever needing Fields just like they killed teams last year without Fields, or they don't, and Fields wouldn't have saved it anyway.
The one thing I'd worry about without Fields is scoring without his running, but then again, if they can't score without relying on a really fast QB running option plays, they deserve to look foolish.