The biggest lesson might just be that Rudi Garcia's Roma is not quite the Giallorossi of old.
Quite the contrary, actually -- last season's side was a team built upon as formidable a defence as the club had in more than a decade, a midfield that was nearly always in sync, and an attack that could not stop scoring goals when fit and healthy.
The Frenchman turned a team that was known for playing beautiful football but having blackouts into one that won the first 10 games of the Serie A season for the first time in league history and went unbeaten until January. Were it not for an outrageously deep and experienced Juventus side, last season's Roma would have taken home their fourth Scudetto.
Predicted starting lineup
AS Roma (4-3-3): Morgan De Sanctis; Ashley Cole, Kostas Manolas, Leandro Castan, Maicon; Daniele De Rossi, Radja Nainggolan, Miralem Pjanic; Gervinho, Francesco Totti, Juan Iturbe.
The arrivals of Ashley Cole and Juan Manuel Iturbe are the most notable new recruits.
Cole was brought in as a short-term answer to the side's biggest weakness -- finding a consistent left-back who can contribute to the offense but also keep the back as tight as they have been. He brings a wealth of experience from his time at Chelsea and fits the club's summer philosophy of bringing in trophy winners in order to prepare the side mentally for the Champions League campaign to come.
Iturbe is the exception to that rule; Roma's most expensive signing this window has no European experience at all and just one season in Serie A. The plan seems to be to replicate what Gervinho brings to the other side of the flank to help the side be more ruthless on the attack. Preseason has been a mixed bag for the former Hellas man but his final game saw him draw a foul and score off of the ensuing free kick.
Finally, the late addition of Kostas Manolas was Walter Sabatini's backup plan for losing Mehdi Benatia, which unfortunately came inevitably, given his public decree of wanting to play for a bigger club and his refusal to accept Roma's renewal.
Manolas is highly rated but still young and raw. At just 23, he's four years younger than the man he replaced, but he already has more experience on the biggest of stages, having shone for Greece in the World Cup this summer and in the Champions League with Olympiakos last season. He scored against Benfica and PSG before his side were knocked out by Manchester United in the round of 16.
Roma's season will depend greatly on how well the Greek can fill in for the departed Moroccan; should he replicate his Greece World Cup form, the difference may not be so pronounced, but Benatia's loss is a massive one for Roma nevertheless.
For the first time in years, Roma have genuine depth in every position.
There are no fewer than six forwards jostling for three spots, with the aforementioned Gervinho, Totti and Iturbe competing against the traditional striker Mattia Destro, the creative enigma Adem Ljajic and jack of all trades Alessandro Florenzi.
Kevin Strootman will certainly be fighting for a spot in the midfield when he's healthy, and Salih Ucan and Seydou Keita will provide the much-needed depth and rest the side will need when playing a match every three days. At the back, Vasilis Torosidis will be key, as he can play on either flank, and Davide Astori was brought in to give the centre-backs a rest.
Compared to just last season, when Michel Bastos was brought in to play any position on the flank that needed covering, Rafael Toloi was the third-choice centre-back, and Marquinho and Michael Bradley were depth in the midfield, this season's team has much more experience -- both internationally (Keita) and within Serie A (Astori).
Furthermore, the loss of Benatia aside, the team have kept all of the major pieces. The more recent recruits such as Gervinho, Maicon, De Sanctis and Nainggolan should find themselves only more comfortable with those around them, and Roma's renewals of Pjanic and Castan helped ensure the side would have a familiar spine no matter what happened with the Moroccan.
Benatia's departure has left a giant hole in the back that will not easily be filled.
Roma certainly wanted to keep the league's best centre-back but he wanted out, and the last thing the club needed was to keep a player who did not want to stay. Manolas may turn out to be a great defender in time, but was brought in four days before the season started. Rudi Garcia's biggest test this season will be to integrate the young defender and hope he can keep the back just as frugal about shipping goals as it was before.
The other glaring weakness for the side will be the addition of Champions League games that will test the depth of the side. If anyone can manage the rotation and fatigue that will ensue, it should be Garcia, and the mercato looks to have been conducted with exactly that in mind.
Manager: Rudi Garcia
There's little left to say of a man who transformed Roma so dominantly last season. He's a trophy winner, a superb man manager and tactically flexible -- Roma strayed from his preferred 4-3-3 last season as injuries demanded to a 4-2-3-1 that worked nearly as well. His insatiable appetite and eye for detail are absolutely crucial to what Roma are today. Easily the best manager Roma have had since Luciano Spalletti, he's the only man to start successive seasons at the club since Claudio Ranieri, and he seamlessly combines the former's desire to play beautiful football with the steely nature of the latter's tenure at Roma.
With a side that performed as well as last season, it's difficult to single out any one player who is truly key for this team. Roma will certainly need everyone contributing at a high level to repeat the heroics of last season, but Daniele De Rossi might just be key to it all.
His leadership on the team will be absolutely vital both in Europe and domestically. He shields the back as no one else -- a facet of his game that will need to be at the very peak to help offset the loss of Benatia, perhaps the most integral part of a side that conceded the second-fewest goals in the league last year. For Roma to succeed, they'll need their Capitano Futuro to play as he did last season: a co-Capitano Presente.
An honorable mention to Gervinho -- his form last season was simply his best since his days at Lille. The offense does not tend to work quite the same way when he isn't playing or in form, so not only will the onus be upon him to keep up his ability to create havoc in the box, but he will be needed as a mentor to Iturbe. In that sense, two-thirds of Roma's attack could come from the influence of the man from the Ivory Coast.
Predicted finish: Second
First place may be a step too far for this side with Champions League games in the mix. Should Roma make it out of what is almost sure to be a very difficult Champions League group and remain second, the team will have improved over last season and still have achieved so much.
If the side focuses on the league over Europe, however, first may well be in their grasp, as Juventus surely look to prioritize Champions League pursuits over a fourth consecutive Scudetto, especially given the group-stage exit they suffered last season. It all depends on how Roma cope with the loss of Benatia and how they juggle the demands of Europe, which they did not have last season.