BBC Radio Norfolk reports that Hernandez liked various posts that were critical of the club and head coach Johannes Hoff Thorup.

The 32-year-old Cuban joined the Canaries in January 2018 and has made 189 league appearances, although almost half of them have been as a substitute.

"It's an internal matter that we are dealing with at the moment, so I'll probably not say too much about it," Thorup told BBC Radio Norfolk following the game.

"We've had a couple of incidents this season which I think is normal and happens all over the world in terms of football, but it's just how does the player react and respond to it afterwards?

"It's been pretty clear the whole season what we expect and it's a matter of what the response will be from Onel."

Hernandez's contract with Norwich expires at the end of the season, but does include an option for a further 12 months.

The game against Sunderland ended in a 0-0 draw, leaving Norwich 11th in the Championship and seven points outside the play-off places with five games remaining.

Striker Ante Crnac missed the game because of injury and Thorup is keeping fingers crossed that he will not miss the rest of the season.

"There's not too many games left. He picked up an ankle issue and we put ice on it after the game at Plymouth (on Saturday) and actually thought it was OK and probably just a knock," the Dane said.

"But it was a little bit more than that and he couldn't train. What we will say for now is that it's probably a week or two, something like that. We hope we can make him ready as quickly as possible."

Norwich are next in action on Friday evening when they travel to second-placed Burnley.