Fans of Barcelona were able to wake up with an extra spring in their step on Thursday morning, following Wednesday's reports that the No.10 has reached an agreement in principle to extend his stay with the Catalan club.

Messi has been at Barcelona since 2000, but is currently a free agent after his most recent contract expired on June 30. The Argentine is, though, keen to stay at the Camp Nou. One year after he sent a burofax to Josep Maria Bartomeu's administration to try to leave, Messi is content once again and the newly crowned Copa America champion is looking forward to competing for club silverware in the club's funky new Blaugrana kit in 2021/22.

But, why hasn't an official announcement been made? What still needs to be resolved for the deal to be signed, sealed and delivered? Here comes a look at some of the key questions of Messi's new contract.

Five years that could be two

The player's new contract is expected to be a five-year deal that will link him to the Catalan club until 2026. However, it is widely expected that the No.10 will only actually play for the LaLiga Santander side for the next couple of years.

He could then move to MLS and act as a club ambassador, remaining on the Blaugrana payroll. In essence, the club would be able to spread the money of Messi's final contract over several years.

Messi's pay cut

The forward's previous contract was worth over 500 million euros and was the most lucrative in the history of professional sports. For Messi to stay, given the problems of the coronavirus pandemic and given Barcelona's already complicated financial situation, it was clear that a major salary cut would be necessary.

The reports on Wednesday spoke about a salary reduction of approximately 50 percent. That will be a major help for the Catalan club, not only because it makes Messi's own contract more viable, but because the example it sets for other high earners in the squad could be significant.

LaLiga's economic controls

Even with Messi's huge pay cut, this deal still isn't over the finish line. Barcelona need to register Messi and their other summer signings - such as Memphis Depay, Sergio Aguero and Eric Garcia - through LaLiga and they must meet the league's spending requirements.

With these requirements based on income and savings, and with Barcelona struggling in both those areas, it is still going to be a major struggle to ensure all the jigsaw pieces fit together properly. Again, this is why the payments being made to Messi are being spread over multiple years.

Even still, Barcelona must clear further room off their books before they can officially register Messi and all their new arrivals.

The players who could have to make way

Barcelona have already cleared some wages by moving on Trincao, Junior Firpo, Konrad de la Fuente, Jean-Clair Todibo and Carles Alena. But, this is like putting pennies into the piggy bank and hoping it'll prove enough to save up for a Ferrari.

To clear the space necessary for Messi, a big name star will have to depart. The players most likely to do so are Philippe Coutinho, Ousmane Dembele or Antoine Griezmann, with the latter linked with a swap deal to return to Atletico Madrid in place of Saul.

Barcelona would then have to find a way to register Saul too, but he is a player they have long admired and a player they were given the right of first refusal over when they sold David Villa to Atleti all the way back in 2013.

Sponsors want the deal done as soon as possible

As well as Messi's contract, Barcelona must be careful when it comes to other contracts they hold with their various sponsors. The fact that Messi is technically not a Blaugrana player right now could cause some problems in terms of using the Argentine in promotions.

Sponsors, logically, don't like this uncertainty or the wait to be able to work with Messi again. They'd like the new contract to be ratified as soon as possible and Barcelona would too, especially as several contracts with major club sponsors come to an end in 2021.

For now, though, all everyone involved with Barcelona can do is remain patient. There is an agreement in principle. Now, the lawyers and accountants must dot some i's and cross some t's. Quite a few of them, actually.