While Messi's loyalties are with boyhood club Newell's Old Boys in his native Rosario, the Barcelona superstar said that Tuesday's superclasico semifinal decider is an event that all of the world will be watching.
"Yes, obviously I'll be watching it," Messi said in a radio interview. "I'll be watching it along with all of Spain. Even more so when it comes to a semifinal. The first leg I didn't see it because it was at like 3 in the morning, I watched the highlights the next day, but everyone is watching that game."
Boca will be looking to overturn a 2-0 deficit at home in the second leg at La Bombonera.
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Boca Juniors vs. River Plate (agg. 0-2), Tuesday, October 22 @ 8pm ET / 5pm PT
Flamengo vs. Gremio (agg. 1-1), Wednesday, October 23 @ 8pm ET / 5pm PT