There have not been many tougher nuts to crack in the Premier League this season than trying to beat Sunderland away, but Liverpool did thanks to Virgil van Dijk’s header and the skill and artistry of Florian Wirtz. It was scrappy and messy; a dogfight. Sunderland made it a battle from start to finish as Régis Le Bris’s side did what they have done to so many teams before this season. They were direct, physical and dangerous, but Liverpool stood firm. They showed a steely side on Wearside and in the middle of it all was their little German maestro. Wirtz had initially found the speed and aggression of the Premier League difficult. It all looked a little too much for a player raised in the Bundesliga. A £116m price tag looked as heavy as the tackles he received. Wirtz has been rapidly improving, making the adjustments in his game for some time, but in standing tall in this clash, the 22-year-old looked like a boy turning into a man. There are not many tougher …