Almagro is likely to be slightly fresher than his compatriot, having received a semi-final walkover due to Sam Querrey's decision to pull out with a back injury.
Meanwhile, Verdasco, who is also in the doubles final in Houston, battled past Colombia's Santiago Giraldo 6-4 7-5 in the last four.
"He's really dangerous on clay," said Almagro of Verdasco. "He's serving well. It will be a nice final. We are going to do our best."
Almagro already has 12th ATP singles titles to his name, seven more than Verdasco.