Marmol was lifted from a game last Tuesday and underwent an MRI, which revealed no significant nerve injury. The Cubs closer felt some tightness in his neck and shoulders, as well.
Wood had some back problems early in spring, pitched in four games and has not made an appearance since March 18.
"There's no reason for any extra workload," Cubs manager Dale Sveum said on Sunday about Wood.
The light workload was apparently planned before Spring Training began, Sveum said. Wood has also not had any side sessions. Sveum said the right-hander had no other physical problems.