Arsenal have signed Riccardo Calafiori from Bologna for a 42 million transfer fee, the club announced on Monday, ending a month-long chase for his signature.

The 22-year-old defender had an excellent campaign with Bologna to help the club into the Champions League for the first time ever. But he exploded onto the world stage this summer thanks to some fine performances for Italy at Euro 2024, notably delivering the assist for Mattia Zaccagni's dramatic 98th-minute equaliser that knocked Croatia out at the group stage.

It has been a remarkable turnaround in fortunes for a player who, six years ago, suffered such a severe knee injury that his career was under threat. Indeed, it dwindled for a while -- he dropped from Roma to Genoa to Basel in the space of eight months -- but finally found his feet in Switzerland, earned a 4m move back to Serie A with Bologna in 2023 and hasn't looked back since.

So, what can Arsenal fans expect? Here, we'll outline everything you need to know about Calafiori, digging into some data and analysing his evolution as a player over the last few years.

Position

Calafiori has risen to prominence over the past 12 months as a centre-back, but it wasn't too long ago he was considered a left-back. Almost all of his appearances at boyhood club Roma came as a left-back or left-wing-back, and it wasn't until he moved to Basel where he tried his hand in the centre of defence.

As it turns out, that suited him perfectly. After only a handful of matches, Bologna took the a chance and offered him a route back into Serie A. Playing a full campaign in the centre of defence, Calafiori caught the eye of Italy manager Luciano Spalletti, who opted to give him a starting role at Euro 2024 and shift two-time Serie A champion Alessandro Bastoni over to the right side. Which is quite the compliment.

By the numbers

Perhaps the most pertinent Calafiori statistic is that he assisted five goals last season, the joint-most of any centre-back in Europe's top five leagues. That hints at a wider tactical brief.

*Stats based on Serie A 2023-24 only

Pass accuracy: 89.6% (79th percentile)
Progressive passes: 3.68 per 90 (70th percentile)
Shot-creating actions: 1.76 per 90 (91st percentile)
Tackles + interceptions: 3.72 per 90 (90th percentile)
Aerial duel win rate: 71.4% (95th percentile) Strengths

At 6-foot-2 with a long, powerful stride, Calafiori looks made for the modern centre-back role. But he also looked made for the modern wing-back role, as he can gallop up and down the flank, take shots on goal (there have been games where he racks up four or five) and cross into the box; he was like a more refined Marcos Alonso.

The fact he has such positional versatility and a complete physical profile is his first major strength. It means Arsenal will be able to do a lot with him, and ask a lot of him, and he'll cope.

At Euro 2024, that defining assist for Zaccagni came after a long run through the middle of the pitch, starting at centre-back, beating three players and drawing a fourth towards him, before laying the ball off just outside the opposition penalty area. He's still using that wing-back stride, only now it sees him power into central midfield and beyond, not up the flank.

This summer saw him compared to some truly great Italian defenders of the past, but during the 2023-24 campaign with Bologna, Manchester City and England star John Stones was often the comparison. Calafiori's technical comfort stepping out of the defensive line and into midfield, his ability to progress the ball, and aggression in winning it back high up, all suggest that comparison isn't far off the mark. He's also very strong in the air.

How he can improve

It's tough to find fault in Calafiori's game despite his young age, as he can already do so many things to a high standard and has a gritty mentality, formed by his horror injury at age 16.

That said, there are times when he's perhaps a little too aggressive in tracking his opponent and can be drawn into committing unwise fouls, or goes chasing the ball high up the pitch and gets caught out of position.

Aggression is no bad thing, and you have to accept that front-footed defending can be used against you, but it's still important to channel aggression in the right way, at the right time.

There's also the odd heavy touch that could be ironed out, which is a simple matter of time and repetition in training.

In quotes

"If you want to build up the game and have possession, he's brilliant," Basel manager Heiko Vogel said this summer, per Sky Sports. "If you followed the European Championship, his rushes into the midfield were breaking the opponents' lines. He has a very good heading game in defence and attack, he was very dangerous in front of goal from set pieces."

Calafiori has also spoken on the Stones comparisons, hinting that he was essentially told to emulate him by Bologna manager Thiago Motta.

"Stones is my reference," he said. "His style of play is closest to mine. It's not off-the-cuff when I go into midfield. It's following the guidelines of the coach. He saw me in this role. I've learned oceans off him."

Who else was linked?

Chelsea, Liverpool and Juventus were all credited with interest in Calafiori over the early stages of the summer.

How will he fit at Arsenal?

Arsenal's recruitment has fallen into a recent pattern of finding good footballers, first and foremost, then figuring out how they fit into the team a little later. Specifically with regard to defenders, Mikel Arteta appears to favour players who can play more than one position -- as evidenced by Jakub Kiwior, Takehiro Tomiyasu and Jurriën Timber's ability to play across the defensive line. Even right-back Ben White has been converted from the centre-back role he played at Brighton.

That puts Calafiori in a good spot early on, as he can naturally drop into two positions: left-centre-back and left-back. With Gabriel and William Saliba an unbreakable pairing in the middle last season, chances are Calafiori gets his early minutes at left-back, competing with the oft-injured Oleksandr Zinchenko.

On paper that may sound like a regression for him, as he's more or less left that position behind in the last 18 months, but Arsenal's left-back position isn't exactly standard. There are times where you become the left-centre-back in a line of three, there are times where you have to push into midfield alongside Declan Rice, and there will be times you need to roam up the touchline. As we've established, Calafiori can do all of these things -- and to be clear, there are precious few who can (especially when you factor in being left-footed).

Arteta will be satisfied that the Italian is physically strong and fit enough to cope as a Premier League centre-back, where the athletic standards are extremely high, and that his strong aerial win rate is fit for a division that features plenty of aerial assaults.

Plus, at age 22 (and having lost a fair chunk of time to injury during his teens), there's still plenty of room to grow and improve.