Messi has started the season in spectacular form, registering 12 goals and five assists in 11 appearances for Barcelona in all competitions to fire them to the top of La Liga and to the brink of qualification for the Champions League knockout stage.
Messi is recovering from a broken arm suffered last month, and Barca boss Ernesto Valverde has opted to leave the superstar attacker out of the match at the San Siro, sticking with the same starting XI that scraped past Rayo Vallecano 3-2 at the weekend.
As Barcelona ready themselves to face Italian club Inter Milan on Tuesday (Wednesday in Pakistan as the game would begin at 1am), we take a look at Messi's goals against Italian clubs in European competitions throughout his career. "We know they will score many goals together again". "We talked about it and he understood", Valverde told reporters.
Messi still travelled for the game to show his support for his teammates.
More crucially, key players have delivered while others, less prominent, have stepped up.
According to Sport, all of Barcelona's first team were given the day off to rest up and prepare for their match against Betis on Sunday.
Shiva Singh bowls with 360-degree turn and hogs limelight
But Shiva Singh outdid everyone else - rotating 360 degrees in his run-up just before the delivery during the domestic games. The umpires had intervened when he tried to bowl with the 360-degree turn and called it a dead ball.
However, Messi made a decision to train alone at Ciutat Esportiva in a bid to be fully fit for their match against Betis.
That says so much about Messi.
Despite his desire to be fit for the match, Beits' manager, Quique Setien, has advised Barcelona to keep him on the sideline for the clash. "We were more ambitious and we dominated the whole game".
"Any fall could provoke a serious problem that might have important consequences".
"Leo Messi travels to Milan without medical all-clear", Barcelona said in a message accompanying the revised squad list on their official Twitter account.