Honestly don't see why Bernardeschi would be a much better player than Keita. Haven't seen much of either though, mostly their games against us & highlights.
Keita is great on highlights because his whole game is dribbling and shooting. Which he is really good at, top dribbling and finishing, but other than that there is not much else. The man has 0 workrate, seriously, he is the laziest of Lazio's forward players. Immobile, Anderson, Lulic and Sergej all defend, everyone except Keita.
He has become very effective playing as an SS where he is closer to goal and doesn't have to run/dribble through more players like on the left.
This is good, but we have the best SS in the league in Dybala. We can play Keita on the left, but then its RIP Pjaca. Who is our own dribbler and shooter. Is it worth it give up on Pjaca to fit Keita?
The answer could be yes, I'm not against it.
Now Bernardeschi does everything for Fiore. He plays every position and does it well. Sousa has played him tons as a wingback this season because they have few options there. He plays on the left, right and center.
Above all, he plays for the team. He runs, he defends, he dribbles, passes, crosses and shoots. He understands the game and is able to truly play anywhere. Remember Diamanti who could play any role because in the end he was simply good at football. Bernardeschi is like that but better, a complete player.
Its a player that is very hard to find and is extremely valuable for a team.
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I know, and i wouldn't buy Keita for more than €25m. That's why It's a good opportunity to get him now, without running too much risk.
Your last sentence is basically the "hes italian" argument, we don't pay for ability, but for him being tuskany.
Don't get me wrong, i't's not like i think he's a scrub, i'd gladly take him for around €30-€35m, but not for the sums i read today. We shouldn't overpay that much just because the purple rats don't even want to sell us the dirt under their fingernails.
But you are ignoring the first clause of that sentence that reads "is a much better player"
That's why its worth getting him, not because where he is from.