José Mourinho wants the 24-year-old as part of a summer revamp at Tottenham Hotspur – according to Tuttomercato. Meanwhile, Le10Sport claim Paris Saint-Germain would like to replace Thomas Meunier with Castagne.
Already team-mates for Belgium and rivals for the right-back spot, Meunier is expected to depart the Parc des Princes when his contract expires. In fact, Spurs have also been linked with the PSG star.
Spurs' need for a right-back is born out of a chronic mismanagement of the position in recent years. Having allowed Kyle Walker and Kieran Trippier to depart, only the gung-ho Serge Aurier remains. The Ivorian is great fun to watch going forward, but is a defensive liability. As a result, Mourinho is looking for an upgrade on the right side of defence.
Who is Castagne?
Most kids grow up idolising or looking to emulate their parents and Castagne was no different. His father, Pierre, was a professional who twice finished top scorer in Luxembourg in the 90s.
Born in Arlon, Belgium, Castagne Jnr. started out with Genk, making his Belgian Pro League debut in September 2014 against Club Brugge in a 1-1 draw. On the other side that day? The aforementioned Meunier.
Over the next three seasons, Castagne established himself as a regular with the Blauw-Wit, making 99 appearances in three years, including 49 during his final campaign in his homeland as Genk went deep in the UEFA Europa League.
Castagne joined Atalanta in July 2017 as a replacement for Milan-bound Andrea Conti, having outgrown the Belgian Jupiler League,
What are Castagne's strengths?
Predisposed to attack at every opportunity, Castagne is the perfect fit for Gian Piero Gasperini's attack-minded Atalanta side.
What is clear is that Castagne is a threat whenever he goes forward. Regardless of which side he's deployed on, he is constantly looking to overlap.
In the image below, taken from Atalanta's 2-1 win at Fiorentina in February, Castagne demonstrates his threat going forward. Fiorentina left-back Dalbert has completely switched off to the Belgian's threat and he is able to progress into a dangerous position.
Castagne has the awareness to spot the run of Mario Pašalić arriving very late into the penalty area. He cuts the ball back for the Chelsea loanee, who is in acres of space but somehow places it wide of the near post.
In another match, this time against Genoa, Castagne again finds the space for a dangerous delivery. Onceagain the full-back is oblivious to the threat of the former Genk defender. Having received the slide-rule pass into the box, Castagne cuts onto his left and tries a shot, which results in Robin Gosens bundling home.
Give his tendency to bomb forward, it comes as no surprise Castagne averages 2.09 touches in the opposition's penalty area per 90. Furthermore, he provides one shot assist and 1.25 accurate crosses per 90.
Although the Belgian international has only supplied a single Serie A assist this season, profligate finishing is to blame. He is on-track when compared against his xA total (0.78) for the season. It's also worth mentioning that he has never been prolific in providing assists – just eight in his league career, per Fbref.
What are Castagne's weaknesses?
The big drawback to Castagne is something Spurs already have problems with. Current right-back Aurier is a menace going forward, mixing pace and penetrative runs deep into the opponents' half. Castagne isn't quite as athletic as the Ivorian but offers a similar threat.
But like the former PSG defender, Castagne is regularly caught out too high up the field. Gasperini's 3-4-1-2 system compensates to some extent with three central defenders. They enable Castagne, Gosens or Hans Hatebor to roam at will.
When it comes to active defending, Castagne isn't bad. He's strong in the tackle, physical and his tireless running and pace mean he has no problem getting back. But he is prone to diving in or being shown up defensively in one-v-one situations.
The biggest issue, though, is being in the right place to begin with. In Serie A this season, Castagne has won 3.58 of 5.25 defensive duels per 90 and claimed 3.75 interceptions. He has also lost 8.42 duels with more than a third of those incidents taking place in his own half.
On that basis, Castagne would arguably be a better fit for PSG. Les Parisiens expect to dominate possession in every game and his natural athleticism would be put to its fullest use. While he might not be ready for a huge move, it's clear Castagne has the potential to far exceed his father's exploits.