Off the top of my head, Keane and Rio had similar incidents.
Herrera has been on the bench for the last 18 months. It's quite likely the club are attempting to pay him as such. He wants to be first choice and that looks likely going forward, and the hold up might be that he's asking for that level of pay.
Equally, and probably more likely, he simply wants to be play as first choice and is waiting to see how likely that looks. Ultimately, most players reach a point in their late 20's where they don't want to be squad players anymore and wish to play the majority of games. I don't think anybody would accuse the likes of Nicky Butt, John O'Shea or Phil Neville of not loving the club, but they all made that move. Nobody holds that against them, and Herrera is now facing the same situation.