"We've talked about it with the staff," Roenicke said. "We're still working on it."
Marcum was placed on the 15-day disabled list on June 23, retroactive to June 15, with right elbow tightness.
"In the next 10 days, I don't think he's going to be ready to be a starter," Roenicke said. "So we're just planning on him not being there for a little bit. The nice thing is [Mike] Fiers slipped in there and is pitching great. [Marco] Estrada slipped in there and he's pitching great.
"So, we need to get Shaun healthy. Instead of pushing him to come back, we really need to get him healthy and when he comes back to have that same really good pitcher as when he went out."