While the beautiful game will lose its most prolific artist, Los Blancos' chances of domestic and El Clasico dominance will be seriously increased.
Messi's career has coincided with Barca's most successful period in the club's history, with the Argentine collecting 32 trophies with the club since 2005.
In El Clasico, Messi has been Real's chief tormentor, scoring 26 goals in 39 games against the Blaugrana's eternal rivals.
No player in the history of football's most famous game has managed more goals than the 32-year-old and his sparkling form in 2018/19 suggests he will seriously add to that in the years to come.
Messi already has 33 goals in all competitions to his name, more than any player in Europe. Karim Benzema currently leads the way for Real with 19, 11 of those coming in La Liga.
But what if the two were playing together in the famous white shirt this season?
Well, the folks over at Planet Football have tried to play out that scenario by simming Real's 2018/19 season on Football Manager with Messi added to the squad.
AUGUST-NOVEMBER - REAL DOMINATE A GREIVING BARCA
With the city of Barcelona in mourning after the loss of Messi, Real get to work with the mercurial Argentine and take La Liga by storm.
After 12 games, Los Blancos have won 11 and have drawn just one, with Messi scoring eight goals.
As for Barca, they're 15 points behind after amassing just 19 points from their 12 games, including a winless November.
Ernesto Valverde somehow manages to keep his job...
DECEMBER-MARCH - BARCA BEGIN HEALING PROCESS
In the what would be the most hostile El Clasico atmosphere of all time, Barca get some revenge by beating Real 1-0 in the Bernabeu.
The Blaugrana go on an unbeaten run until mid-March, but three winless games after makes even a top four finish unlikely.
Real simply keep going strong with the odd blemish here and there, maintaining their place at the top of the league and into the latter stages of the Champions League.
After 34 La Liga games, Messi has 20 goals and nine assists to his name.
APRIL-MAY - REAL WIN TREBLE, BARCA FINISH FOURTH
That's right, Messi helps guide Los Blancos to their first ever treble, beating Manchester United in the Champions League final.
With La Liga sewn up, Real rest Messi for the Clasico in the Nou Camp just to troll Barca fans even more - the game finishes 1-1.
The two sides meet in the Copa Del Rey final, but Real come out on top again as Messi scores the opener in a 2-0 win.
Barca have to make do with fourth spot, sitting 17 points behind Los Blancos in the table.
Thankfully to Barca fans, this horrific scenario will never become a reality.News Now - Sport News