Halladay, 35, is 10-8 in 24 starts. His 4.40 ERA is his highest since he finished at 10.64 in 2000.
Halladay visited doctors again on Sunday, and general manager Ruben Amaro Jr. said on Monday, "After the last exam, it seemed like he's OK for his next start. That may change."
According to Amaro, no further tests are scheduled, and Halladay could still face the Nationals on Thursday.
"He seems to be doing OK," he said. "If anything were to change, the doctors would give us anything or Doc would give us anything, then we'll let you know."
There are two schools of thought when it comes to Halladay making his final two starts.
1. If there is no risk of injury and Halladay wants to pitch, let him. He has earned the right. And consider this: Who would pitch in his place? The Phillies really have nobody, as the Minor League seasons ended weeks ago, unless they want to use the bullpen in those starts.
2. Even if there is no risk of injury, Halladay should rest in anticipation of 2013, since there is little left to play for. The Phillies are five games behind the Cardinals for the second National League Wild Card spot with just nine games to play. Even if the Phillies finished 9-0, they would need the Cardinals to finish no better than 2-7 to forge a tie.
Amaro declined to address the positives and negatives of both scenarios.
"We haven't discussed it internally yet, but we'll see," he said.
But looking ahead, there will be less certainty regarding the Phillies' rotation entering Spring Training than there has been in the recent past. In 2011 the Phillies had the four aces (Halladay, Cliff Lee, Cole Hamels and Roy Oswalt). This year there was no reason not to believe that Halladay, Lee, Hamels and Vance Worley would deliver the organization its sixth consecutive trip to the postseason.
But as Amaro begins his offseason to-do list, he seems pretty comfortable with his rotation.
"I like our rotation coming into next year, barring any other issues," he said. "I like our top four or five guys coming in, and we have a lot more depth coming from below. I like our situation a lot as far as our starters are concerned, yeah."
Worley underwent surgery earlier this month to remove a loose body and spur from his right elbow, and he should be ready to go by Spring Training. Kyle Kendrick, 6-2 with a 2.17 ERA in his last eight starts, is a heavy favorite for the fourth or fifth spot in the rotation.
"[Kendrick] hasn't done anything to make us think otherwise," Amaro said. "He's pitched very, very well over the last half of the year. ... I don't know if there are many better fourth or fifth starters in the league."
But what about Doc? Can he rebound? Or is there just too much mileage on that right arm?
Amaro is confident that a revamped offseason workout program will get Halladay back on track.
"Yeah, I think we can assume that," he said. "Knowing the way Roy goes about his business and some of the things that he may be able to do, I think the benefit of Roy is even if he's not back to throwing 92 to 95 [mph], he's still going to be a top-of-the-rotation pitcher, regardless."