The club didn't like that. Their manager Paolo Di Canio didn't like it either, and now he has another reason to feel anger towards the full-back.
Per the Sun, the injured Bardsley appeared to be relishing Sunderland's opening-day Premier League defeat when he responded to a picture posted on Instagram.
Bardley's message was quickly deleted, but Sunderland have banned him training and launched an investigation into his alleged antics.
Together with his casino cameo, he's had a Bleacher Report yellow card coming. He's lucky it's not a red.