The ex-Arizona Diamondbacks reliever shared the positive update in a post on his Facebook page Tuesday morning ... writing, "Thanks to EVERYONE who got involved."

His wife, Sarah, added her thanks in a message of her own on the social media site as well.

So far, details surrounding her whereabouts have not been released. Missing In America Network -- which helped get the word out about Brenna's situation -- asked fans in a statement "to give the family space and grace to work through the situation without judgment or intrusiveness."

The Swindells first reported their daughter -- a single mother of three -- had gone missing last week from the Austin, Texas area. They suspected she was with her ex-boyfriend in a white KIA ... and in ensuing updates, the family stated Brenna and the man had been spotted in Colorado over the weekend.

At the time, Greg said the Swindells were worried sick ... writing in one Facebook post, "we feel she is in danger."