When Gonzalo Higuain split Italy by moving from Napoli to Juventus for an Italian record €90m, many eyebrows were raised at Napoli's choice of replacement for their free-scoring striker.
The man Napoli brought in to ensure the goals kept flowing was the then 22-year-old Polish stirker Arkadiusz Milik, brought in for €34m from Dutch side Ajax. With the exception of a three year spell with Bayer Leverkusen (one of which was on loan at Augsburg) in Germany, where first team chances were hard to come by, Milik was untested in one of Europe's big leagues.
Despite the scepticism of many, and his lack of experience in comparison to the six years his senior Higuain, Milik hit the ground running, scoring two braces in the opening four games of the Serie A season against Milan and Bologna.
He also found the net three times in the Champions League group stages, with the striker's pace and physicality making him a menace for Serie A defences.
Heading into the October international break, Milik and Napoli sat second in the Serie A table, just four points behind leaders Juventus. It was during that international break however, that Milik and Napoli's season changed dramatically.
While playing for Poland against Denmark, Milik tore his anterior cruciate ligament in his left knee, keeping him out until February. Milik didn't start another league game all season, and Napoli were never higher than third in the table again.
Despite making his long awaited return in the new year, Milik's return was an all too short one.
In just his third appearance of the Serie A season, Milik once again found himself facing another spell on the sidelines, after once again tearing an ACL, this time in his right knee, having come on as a substitute against in a 3-2 win over newly promoted SPAL in late September.
The Pole is now in the midst of another long spell on the sidelines, and this time, his chances of winning back his place in the side like far more challenging. Unlike last season's title challenge, which quickly fell away after that October international break, this season, Napoli - despite a recent wobble - are right in the mix of an open title race. They're top of the table.
Maurizio Sarri's side have lost just once in 18 Serie A games, and sit one point clear of defending champions Juventus as the season approaches its halfway stage.
Milik meanwhile, is looking at the prospect of a loan move to mid-table Chievo Verona in order to get playing football once more.
It is a stark reminder of how quickly a player's career can change. Little over a season ago Arkadiusz Milik looked set to become Naples newest darling, capable of producing both from the start, as he did against Milan, and from the bench, as he did against Bologna.
Now, as his side mount a serious and genuine title challenge, Milik is forced to watch on plan for his potential return to be made from afar, at times, it really is a thin white line that footballers walk across.