Juan Martin del Potro has followed Britain's Andy Murray in withdrawing from the French Open.
The Argentine former US Open champion revealed he was suffering from a virus after losing to Frenchman Benoit Paire in the Rome Masters last week.
World number two
from Roland Garros with a back injury.
Former world number seven Mardy Fish, 41st in
, and his fellow American Brian Baker, 71st, have also pulled out.
Del Potro, the world number seven, made the
quarter-finals of the French Open
last year, losing to Roger Federer.