Noesi, who was picked up for cash considerations or a player to be named later, is expected to fly to Texas Sunday and figures to serve as a long reliever.
"He'll give us some length in the pen," general manager Jon Daniels said. "He's started and pitched in the bullpen in the big leagues. He hasn't really had the success yet that I think people thought he would coming out of the minor leagues but he's 27 years old, durable, good arm, plus stuff. The raw ingredients are there."
Noesi was designated for assignment by the Mariners after pitching in two games this season. He allowed three runs in an inning of work before he was let go.
He came to Seattle from the New York Yankees as part of the Michael Pineda for Jesus Montero trade. He's pitched in 64 games in the majors, going 4-16 with a 5.64 ERA.
The Rangers cleared a spot on the 40-man roster for Noesi by moving Jurickson Profar to the 60-day disabled list. The club will have to make a move to add him to the 25-man roster.