Because Blanco now feels good enough to play, the Mets had no need to retain Santos on the roster. They will fill his roster spot prior to Tuesday's game -- most likely with outfielder Jesus Feliciano, who is batting .385 for Triple-A Buffalo.
The Mets do not plan to make an official corresponding roster move until Tuesday.
Earlier this week, the Mets designated Gary Matthews Jr. for assignment in order to make room for Santos. The move was designed to protect Blanco, who had a successful cortisone injection to relieve the pain in his neck.
"There's no pain," Blanco said Sunday morning. "I actually think the shot is working pretty good."
Blanco was batting .286 with one home run in 49 at-bats before the injury.
Feliciano, who went 0-for-6 for Buffalo on his 30th birthday Sunday, should slot onto the Mets as a fifth outfielder and another left-handed bat off the bench. A .281 career hitter with minimal power over 12 Minor League seasons, Feliciano is nonetheless one of the hottest players in the entire organization.