The Welsh club face the Swedes on Thursday after a comfortable 4-0 win at the Liberty Stadium last week.
"This group of players certainly won't be heading out there thinking it's all over – there will be no easing up," Rangel told the club's official website. "Malmo are at home and they will want to put in a strong performance.
"Every player in this squad knows that they have a massive challenge to be included in the manager's starting XI, so every opportunity we get we must take."
Swansea start the new Premier League campaign at home to champions Manchester United on August 17.