To make room for Cedeno on the 40-man roster the Rays transferred catcher John Jaso to the 60-day disabled list Monday with a bruised left wrist.
Rays manager Kevin Cash said before the Rays opened a three-game series at Yankee Stadium that Cedeno wouldn't join the team for a couple of days.
Cedeno has had a busy week. He was dealt to the Dodgers for cash by the Nationals on Wednesday after appearing in five games this season for Washington, allowing two runs in three innings. Los Angeles designated him for assignment Friday.
In 55 innings over five big league seasons, the lefty specialist is 0-1 with a 4.30 ERA and 54 strikeouts.