Saunders had a 1.50 ERA in 10 appearances with the Tides. He was signed after going 0-5 with Texas in a stint that ended with a poor showing against the Orioles at Camden Yards.
He said Monday: "It's funny because I was in the visiting locker room, I left, and now I'm back in the home clubhouse."
Saunders has spent most of his time in the big leagues as a starter, but worked in relief at Norfolk and will have an identical role with Baltimore.
Saunders pitched for the Orioles in 2012, when he won the wild-card game.