Moore announced his retirement this afternoon less than 24 hours after reportedly accepting an offer from the Cowboys.
Garrett confirmed that they were close to signing the former New York Jets guard but respects his decision to stay with his family.
"We had conversations with him and we thought he might come in and help our team out," Garrett said.
"The conversations were way down the road and we thought we were close to an agreement with him, and he decided when he awoke up this morning he didn't want to play football anymore.
"So we respect that decision. We'll continue to try and evaluate that position as we go forward."