The Marlins placed Caissie on the 10-day injured list Sunday due to a lumbar stress reaction.
Caissie was initially diagnosed with hamstring tightness after being removed from Saturday's game against the Dodgers. However, further tests have revealed a lower-back injury for the 24-year-old outfielder, and he won't be eligible to return until the last week of the regular season. Xavier Edwards (thumb) was reinstated from the 10-day IL in a corresponding move, and Esteury Ruiz figures to see more playing time in the outfield for as long as Caissie is sidelined.