After Reuben Tejada was injured earlier in the week with a strained quad, the Mets had been relying on Justin Turner and Jordany Valdespin at shortstop.
Cedeno had been on the disabled list with a intercostal strain, but played his first minor league rehab game with High-A St. Lucie on Thursday night. He went 0 for 4 in the game, but the Mets are desperate enough for infield help that he wasn't given any more rehab time.
Cedeno batted .249 with two home runs and 32 RBI last season with the Pittsburgh Pirates. He's a career .246 hitter.
No corresponding move has yet been announced, but Valdespin could be in danger of being sent down to the minors.