Yeah, I know what you're asking – again, I don't know the answer. He did dominate the 2-legged EL time vs Chelsea when he was at Basel, that's when I first noticed him. But that's also not an indication of anything, because he had a power of surprise on his side then – it's much harder to deliver when the teams prepare a plan to neutralize you (like they always do against Coutinho in our games). His record against Italy's top teams (league and cup) is quite respectable for a winger:
vs Juve 7 games, 2 goals, 1 assist
vs Lazio 6 games, 2 goals, 0 assists
vs Napoli 5 games, 1 goal, 2 assists
vs Inter 5 games, 1 goal, 0 assists
vs AC Milan 3 games, 1 goal, 2 assists
My working assumption with him is that no, he's not the player who will generally dominate games by himself and find an extra level when the rest of the team is not clicking – he's not a Gerrard or Suarez. However he would give our team badly needed tools such as speed and goals, which can improve our overall balance and make it less dependent on Mane (with January of 2019 excluded). In other words, my expectation for him is similar to what I had for Mane a year ago – I think Sadio has exceeded that expectation somewhat and I hope Salah, who is still quite young at 24 and obviously highly ambitious, can succeed in a similar way. I think a player with Salah's qualities and versatility can be a powerful weapon in the hands of a manager like Klopp.
Here he is making Koulibaly's day rather difficult: