Ross was due to pitch for one of the club's minor league affiliates this weekend, his third rehab start since going on the disabled list July 3 with right shoulder inflammation, and manager Dusty Baker indicated earlier this week he would probably be ready to return to the team after that.
But Ross continues to deal with soreness in the shoulder, so the Nationals decided to end his rehab assignment for now. He can start a new one once he's ready and still be allotted a full 30 days before he's required to come off the DL.
"Nothing changed," Baker said. "Just that he's still a little sore. You want to get that soreness out there. Plus, they get to start their rehab over again. That's No. 1. You only get so many rehab days, then you take them off, you get to tinker all over again in case it takes longer than we hoped."
Ross was briefly in the clubhouse this afternoon while reporters were in the room, but after speaking with a member of the team's public relations staff, he departed and didn't return while the clubhouse was still open.
He expressed optimism last week that things were going well, though admitted it was "pretty frustrating" to have to watch from the dugout as others took his starts.
The Nationals have used prospects Lucas Giolito and Reynaldo Lopez in Ross' place over the last month, with each right-hander making two starts but combining to surrender 17 runs in only 15 2/3 innings. The Nats can avoid using a fifth starter until August 16, thanks to several off-days in the schedule, but it seems unlikely Ross will be ready to return by then.
"We're trying to figure out what to do," Baker said. "Sometimes, he's still a little sore. We've got to figure out what exactly to do. I hate (saying) I don't know, but I don't know."
Stephen Drew, meanwhile, was back at Nationals Park today, still dealing with dizziness but not as consistently as he was last week when he had to be placed on the DL.
The veteran infielder has taken just one at-bat since July 17 - he wound up producing a walk-off double in that at-bat - while dealing first with a violent illness and then an inner ear issue that appears to have been the byproduct of the original ailment.
"It's the sickness," he said. "I didn't have (anything) to eat or drink for four days, literally nothing for four days, with a high fever, and you can't cool it down. It's kind of a bummer, because that's what affected it. Never would have thought that, but looking back at the circumstances with the sickness, it definitely plays a part in it."
Drew said he's had more good days than bad ones this week, and he has been able to participate in some baseball activities. But he won't be cleared to play until all of the symptoms are gone, and he has no way of knowing when that will be.
"The guys here are doing a good job, we're pretty much on top of it," he said. "I wish I could tell you a day - "I'm all ready to go now" - but I can't put myself in that situation where I still feel the way I do and things kind of lag around. I look around and things are still trying to catch up. We've got to take care of this."
Drew said doctors assured him this current condition is not related to concussions, which he has suffered from in the past.