Owens, 6-3, 255, was a fifth-round pick of the Detroit Lions in 2002 but he has only five catches in 24 career games.
Owens played with the Lions in 2002 -- he had all his catches that season -- before being waived in October 2003 and then being claimed by Chicago.
"To get a blocking tight end, that's something we've always had our ear to the ground to get," said Coach Nick Saban. "Our hope is that maybe this guy can be more of a true blocker at tight end."
The tight ends on the Dolphins roster currently are Randy McMichael, Lorenzo Diamond, Donald Lee, Alex Holmes and Jason Rader, but all of them are more pass-receiving tight ends than blocking tight ends.
As far as Ayanbadejo, he's a tremendous special teams player who has very limited experience on defense. Saban said Ayanbadejo had done a fantastic job all summer, but the Dolphins probably have more linebackers than they can use.
Saban mentioned the return of Eddie Moore as being a factor in Ayanbadejo's departure, an indication that the former second-round pick is being counted on in some capacity this season.
Middleton, meanwhile, was let go because an injury he sustained last year prevented him to getting into the kind of physical shape required to make a contribution.
"We thought it was a risk that would be worth it that he could help us," Saban said of Middleton, who was signed on Aug. 3. "If he was in shape, he probably could have."