The Nou Camp superstar fractured a bone in just the 23rd minute of last Saturday's 4-2 win over Sevilla.
Messi, 31, will miss Sunday's El Clasico against arch rivals Real Madrid and has more than two weeks of rehab left.
This will be the first derby without Messi or Cristiano Ronaldo since 2007.
But he did not look too bothered while taking his seat at Barca's home ground tonight.
And having little Thiago, five, next to him no doubt lifted his spirits.
Messi wore a Barcelona jacket for the occasion, with his right arm resting in the sling that hung in front of his white adidas shirt.
And he broke into a huge smile in much the same way he did when pictured out and about in his sling yesterday.
A Barcelona statement on Messi's injury read: "Tests carried out on the first team player Leo Messi have confirmed that he has a fracture of the radial bone in his right arm.
"He will be out for approximately three weeks."
Thiago is the oldest of Messi's three sons with wife Antonella.
Mateo is three and the youngest is seven-month old Ciro.
Source: Read Full Article