Going from Serie A to the Premier League seems to be one of the more difficult transitions to make, although I do think that he managed to play his way into the Liverpool game and ended up doing OK in the second half. Also, it would have been better had he not been rushed back from what looked to be quite a bad injury at the time, but unfortunately the squad is paper-thin in terms of quality.
Another issue is that he's being played into trouble a lot, especially now that there's no out-ball up top. The midfield has a decent balance to it when all are fit and on form, but Doucoure isn't the slickest in possession and Sigurdsson doesn't know what he's doing in there, so they're going backwards to Allan because they can't just knock one down the line for Richarlison to chase. As a result, he's getting swarmed.
I hope that Gomes is back in at Newcastle. I know he chews the ball too much when he's not playing well, but he's always willing to receive under pressure and his short passing is sharper than Sigurdsson, Davies or Delph's.