We're not elite level athletes
Plenty of elite level athletes smoke, drink, eat the wrong things and do all manner of stuff that isn't optimal. Always have, always will.
Obviously if he's gone out on the lash and called in sick the day after, that's not good but it doesn't need to be a huge deal. Ten Hag should give him a massive bollocking privately but make a joke out of it/ignore to the media and move on.