Barca went three points clear at the top of the table this weekend and Messi told the News of the World: "Football is now a big-money game and we know the money that the big clubs are prepared to pay for players.
"Madrid has spent plenty of money on players in the past and broken transfer records.
"Their fans demand success so they are trying to assemble a team that will be able to compete with the very best.
"I just worry about my team though and we hope to have a season like last season and not worry about what anybody else is doing, what other clubs do is not important for me.
"We have great players and a great coach and the confidence levels for this season are very high."
That confidence has been boosted by Messi's new contract - a £200,000-a-week deal that runs until 2016, with a £300million transfer fee if any other club had the temerity to inquire.
But when Messi talks of how the riches don't register with him, even the most cynical would be convinced.
He says: "To me, football is the most important thing.
"It is more important than the money and the personal glory. When I am on the pitch, it doesn't matter if it is a Champions League Final, I feel like a child.
"When I am running with the ball, nothing else matters and I think I am the only person that exists in the entire planet.
"When I am playing football I am totally free - no amount of awards or money can buy you freedom that is why I am so totally in love with the game."