The 28-year-old was a hit for Colorado in the MLS last season, scoring 14 goals.
“Aston Villa contacted us a few weeks ago with interest to see Omar up close,” Rapids managing director Jeff Plush confirmed.
“After discussing the opportunity with Omar, we felt it would be a good chance for him to get a leg up on pre-season training and at the same time get the experience of training with a Premier League club.
“Omar is a Colorado Rapids player. We explained to Aston Villa that we would be open to discussing a loan agreement for Omar until our season starts on March 19 if it benefited Omar and the Colorado Rapids.”
He added: “It would take Aston Villa or any club making a significant offer for us to even consider transferring Omar.”