Sunday's World Cup final pits holders Argentina against European champions Spain in what should be a thrilling clash as each side knocked out France and England in the Semi Final.
With 19 goals, Argentina side have scored the most at the tournament and will be aiming to become the first nation in history to win four consecutive major tournaments.
Meanwhile, Spain are unbeaten in regulation time in 37 consecutive matches and need one more to break the all-time record for a European nation.
Both teams are in incredible form ahead of the final and speaking to Copeabout, Deco admits that he is divided over which side to support heading into the biggest game in world football.
"I always go with my own people, but my people are everywhere.
"Leo (Messi) is always one of us. In the end, it’s hard to choose. On one side, there’s Leo, who, besides being a friend, has given everything to those of us who are Barca fans and football fans. He’s a legend. For me, what he’s doing is spectacular.
"On the other side, there are the lads, our Barca lads. It’s always tough, difficult. That’s why we’ll be paying close attention to everything tomorrow. I think it’s going to be a spectacular final.
“Leo is playing spectacularly. That’s why I think it will be a great final. Both teams have fantastic players. Spain is playing well and Argentina has struggled in some matches, but ultimately it comes down to the heart of the team."
Following the final, Deco will return to chasing down Atlético Madrid striker Julian Alvarez and unveiling Karim Adeyemi who is set to sign for Barcelona this week.