All eyes may be on the reaction of the Inter Milan fans to Zlatan Ibrahimovic's arrival back at the San Siro, but there will be another striker on show on Wednesday night who has a point to prove to his former employers.
Ibrahimovic may now be wearing the stripes of the Blaugrana, but it was Samuel Eto'o who elevated himself to become one of the club's top ten all-time goalscorers in a five-year association with the club, before making way for the Swedish striker and being forced to build himself a new career in Italy.
Eto'o's exit from the Nou Camp was shrouded in mystery. The striker had one of his most productive seasons ever, helping the club to win the Spanish treble with 34 goals in 44 appearances , but was deemed surplus to requirements to the extent that Barcelona coach Pep Guardiola was willing to sell him AND part with £35 million for a chance to sign Ibrahimovic.
Many believed Inter got the best of the deal, but the reasons for Guardiola's decision remain unclear. His public statement was unusual, as he claimed: "There are no footballing or personal reasons or anything about his behaviour. It's simply a question of 'feeling', and that's how I feel.''
Eto'o claimed recently he had no idea why the club had decided to let him go, telling Catalunya Radio: "Since the moment I joined Barcelona and since my very first game for them, I did all I could to do the job asked of me. I never refused to do anything, unlike some of the other players at Barca who said no, and refused to play there.
"I didn't have any problems, but okay, if Guardiola said that I had no feeling for the club, that's his opinion. I always committed myself, and I will show him that this week," the 28-year-old added. ''My only problem now is that I still have no idea what he means by this 'feeling'."
With only a season left on his contract, the ''feeling'' may be that Eto'o lacked the commitment of others at the club. Rumours of dressing-room disharmony under the previous coach, Frank Rijkaard, did not help matters; but nor did the player's own behaviour. His refusal to come on as a substitute in a league match against Racing Santander in February 2007 sparked criticism from the press, his manager and (incredibly) from that shining example of work-ethic Ronaldinho who accused the Cameroonian of not putting the club first.
From then on, Eto'o looked a marked man. And it proved so upon the appointment of Pep Guardiola. The Nou Camp legend, for his part, is not lacking in managerial acumen despite his relative lack of experience and knows what makes the club tick. He made it clear immediately that the trio of Ronaldinho, Deco and Samuel Eto'o were not part of his plans for the coming season and began to build for his own vision.
With Ronaldinho quickly sold to AC Milan and Deco to Chelsea, Guardiola, though, reaped the rewards of keeping Eto'o for one more season. The summer scrabble for his signature - including a bizarre link to Uzbek side FC Bunyodkor - failed to warrant any actual offers, but his goals spearheaded the club's drive for success and he was able to develop an almost telepathic understanding with his fellow forwards Thierry Henry and Lionel Messi. However, after such an amount of speculation, his time in Spain always looked likely to end before his contract did.
The key point from the player's point of view appears to be that he did not feel supported by the club. He could happily make a claim to be the best striker in the world based on current form, but Barcelona's refusal to give him a contract with increased wages appeared to be the final straw after a number of incidents (including a training ground row with Guardiola) that soured his perception of the club.
Offered just a two-year deal on the same terms as before (hardly pocket change but we've been here before with the Ashley Cole saga), Eto'o is a player that needs to feel wanted. His leaving cannot be blamed on a declining relationship with the Barcelona fans - unlike Emmanuel Adebayor's high-profile exit from Arsenal to Man City this summer - but, instead, on a growing dissatisfaction with the running of the club. If he scores against his old side on Wednesday, perhaps a gesture towards the directors' box (rather than the away fans) can be expected.
Some would argue that Eto'o is more likely to hit the net during the game than his replacement, Ibrahimovic, especially in a competition in which the Swede has struggled to make an impact in the past. A sublime strike against Parma at the weekend gave notice that Eto'o is a man with something to prove and two goals in three games suggests that he will hit the ground running; although Zlatan has also been receiving rave reviews for his start to his career in Spain.
As Zlatan may benefit from working under Guardiola, Eto'o seems to have found a new lease of life under Jose Mourinho at Inter. Having claimed that he had wanted to work under the Portuguese boss for some time - despite a falling out when Barcelona met Chelsea in the Champions League four years ago - the striker made it clear that he would ''work to repay him the faith he has shown in me." An interesting statement, given the reasons for his move and his tempestuous relationship with Guardiola.
Clearly feeling that he was treated badly during his final years at Barcelona, the Cameroonian may have been a victim of Guardiola's desire to shake up the dressing room; a reminder of an era in which player power had more of an impact. The coach admitted that letting such a talented player join Inter may have been a mistake; but Eto'o will be hoping to show him first hand, just how much of a mistake that was.