The thing about Vlahovic is before last season, he was going to be sold by Fiorentina. They are the team I follow in Italy and he started the season poorly missing an open goal vs Inter and being at fault for their comeback (they won 4-3 in the last minute). Was a great game actually!
He was awful under Montella and he constantly changed between Vlahovic, Cutrone (yep, the ex-Wolves guy) and Koaume. So he defo was not 'great' at that stage (last season still!)
Then Montella got sacked and Iachini came in. Fiorentina started playing some awful, sit-back and long-ball counter football (akin to Mourinho) but he started playing better. He basically scored the important goals and held the ball up well and etc. He defo sacrificed himself for the team.
Then the last Manager Prandelli came in (Fiorentina had 3 managers last season) and he was unreal. Under Prandelli, there was a tactical change and they tried to attack more.
When people say he had 1 amazing season, I feel that is kind of untrue. I feel like he was amazing come season end but was not so impressive since the first game of last season.
On the flipside, he played really well or excellently under 2 managers with completely different tactical approaches and philosophy and he delivered, showing that he is probably not a one-trick pony as a striker.
I think he has what it takes from a physical, technical and from all reports, psychological point of view (is hungry) but i'd be very careful. He was hot stuff for less than a season, really.
I'd have gone for someone more established (Lukaku) where you definitely know what you are getting but what are the chances that a player of that calibre comes to us?
I guess we'll have to take a pun on potential. Vlahovic could be that guy, but wouldn't bank on a guy that was amazing for 6 months either...