Sadio Mané's arrival at Liverpool was greeted with a lukewarm response. Some believed he was the real deal; many thought he was consistently inconsistent while others were just fed up with the Reds raiding Southampton for a third consecutive summer.
All three groups had valid points. While at Southampton and Red Bull Salzburg, Mané showcased just how devastating he could be playing on the left side of the attack and cutting inside.
His incisive runs combined with his electric pace and ability to finish on either foot meant he could be a weapon in any forward line across the world. He spread 70 goals over four seasons for the two clubs.
However, those claiming he was inconsistent had a point, too. In his first season at St Mary's he went almost three months without a goal or an assist. In his second season in England a goal eluded him for the best part of five months.
Jürgen Klopp's Liverpool side were already inconsistent going forward, it was easy to understand why fans may have been reluctant to consider Mané the man to fix those problems.
Then there were those who liked him as a player and saw his value. But the whole buying from Southampton again thing irked them. Especially when those who have moved north have flattered to deceive. It wasn't as though shopping there had resulted in great value for money success stories at Anfield.
Adam Lallana and Nathaniel Clyne have had their critics, Dejan Lovren is like Marmite but even his biggest fans are finding it difficult to defend his start to the season and Rickie Lambert? The less said about him the better.
But Mané proved the doubters wrong. Never before, at least not under the ownership of Fenway Sports Group, has a player's arrival transformed the team on the pitch quite like this.
The Senegalese speedster added another dimension to the Liverpool attack. With him the Reds were magic, without him they were tragic. It's no exaggeration, either.
Liverpool evolved with him in the side. They went from predictable to spontaneous. Pedestrian in possession to explosive on the attack. Mané was the key to unlocking the abilities of Roberto Firmino, Philippe Coutinho and Adam Lallana.
He terrorised teams on a regular basis and just had the knack to score goals that nobody else in the Liverpool team could. Think back to the one against Arsenal on the opening day of the season when he put on the afterburners to breeze past the defence before curling home a left-footed effort on the stretch.
How, in the second Merseyside derby of the season, he picked the ball up in a nothing position but his acceleration, close control and desire resulted in him scooting past a number of players before arrowing a shot past the hapless Joel Robles in goal.
He finished the season having been involved in a goal every 124 minutes. He had 13 strikes to his name and five assists despite missing three months of the Premier League season. In his absence the Reds toiled.
They went from a swashbuckling side who looked capable of scoring more than 100 goals in the season and rivalling Chelsea for the title to a team who scored just six goals in eight matches and hobbled over the line to finish in fourth.
He started the 2017/18 season in similar fashion. He scored the first equaliser against Watford in the opening game of the season and it all stemmed from his own good work. He picked the ball up and drove at the defence. He made it happen when Liverpool on the day looked lethargic.
The 25-year-old is the one who really stood out in the all important win over Hoffenheim. His run, fuelled by nothing but desire, was what resulted in the free-kick Trent Alexander-Arnold fired home to give the Reds the lead.
He had what was an otherwise organised Hoffenheim defence chasing shadows. There's been no transitional period from him moving from the right flank last season to the left flank this year, and no signs of him feeling the effects of the injury which brought his debut season at Anfield to a premature end.
Mané was, is and will be the difference maker for Klopp's side and tying him down to a new deal should be priority number one right now, ahead of even the Philippe Coutinho saga.
The timing of Barcelona transfer target Coutinho's decision to hand in a transfer request was poor and he is an important player for Liverpool. He's a match winner and a game changer, but for the reported £130million the Merseyside club are reportedly demanding for him, he can be replaced.
Mané, on the other-hand, is priceless to the Reds, their system and Klopp. With this in mind, perhaps now is the ideal time for Liverpool to table a new contract offer with an increase in his salary to take him into Coutinho levels of pay.
The Brazilian is partial to a moment of magic whereas it's quickly becoming the norm for Liverpool's number 19 to deliver.
The Liverpool system functions without Coutinho but it failed miserably without Mané. That tells its own story.
It won't be long before Europe's best are knocking on the door looking to add him to their attack. Bayern Munich will need to replace Arjen Robben and Franck Ribery, Real Madrid may need to sign successors to both Cristiano Ronaldo and Gareth Bale, if the latter continues to be dogged by injury, and Barcelona will eventually have to go Lionel Messi-less in attack.
Liverpool need to do all they can to ensure Mané is content with life on Merseyside – even if Europe's elite are making googly eyes at him.