Mexico and Croatia will enter the Group A encounter on four and three points respectively, with Moreno and his team-mates aware a draw will be enough for their them to reach the round of 16 at the FIFA World Cup.
And the Espanyol defender is convinced Mexico are ready.
"It will be a very important match for all of Mexico, we have been working for it, know what it entails, a draw or a victory gives us through to the next round," Moreno said on Sunday.
"The team is focused and works to that."
Mexico defeated Cameroon 1-0 in their opening match in Brazil before securing a scoreless draw with the host nation.
Croatia were admirable in defeat, as they lost 3-1 to Brazil on the first day of the World Cup, and bounced back with a 4-0 thumping of Cameroon.
Moreno has come up against two of Croatia's stars while playing for Espanyol in Spain - Real Madrid's Luka Modric and new Barcelona signing Ivan Rakitic - but the 26-year-old is convinced there is more to Niko Kovac's team than their La Liga-based midfield pair.
"They are great players and all (but Croatia are) a very compact team where no one stands out," Moreno said.
Mexico coach Miguel Herrera has selected the same starting line-up in his team's opening two games and confirmed at his pre-match press conference on Sunday that the same 11 players will start against Croatia.
