Vick is still recovering from a pulled left hamstring. It apparently is not severe enough to keep him from being an emergency quarterback, but it's still bothering Vick to the point that there's uncertainty about his availability this week.
After Foles passed for 296 yards and three touchdowns, it's not as simple as just putting Vick back in as starter. If it was, Kelly would have answered the questions without equivocation. But Kelly continues to stop short of saying what will happen when Vick is healthy again.
"Until we know what the health is, I'm not saying what anybody is," the coach said, adding that he treats other positions the same way. "All our decisions on who is going to play [are] based on health."
Kelly said he has not had any discussions with any player about the position, and insisted there is no division about who should start at quarterback. He also said the team understands that "Mike wasn't 100 percent on Sunday and Nick did an outstanding job."
Vick said Sunday that he didn't know whether he would be healthy enough for the Cowboys game. But he eventually will reach 100 percent. That's when Kelly has a decision to make. It might happen this week. Yet "100 percent" can be subjective, and it will be up to Kelly to determine when Vick is able to play to the coach's satisfaction.
Part of the evaluation will be based on Vick's mobility. That's a unique skill that adds value to the offense. Vick has been clear that he cannot rush back and risk reinjuring his hamstring.
Whether it's Vick or Foles, this is a good problem for the Eagles. Vick was effective before his injury and Foles excelled in relief.
After reviewing the film, Kelly said Foles took advantage of what the defense gave him and made decisions that took the Eagles from bad plays to good ones.
Foles completed a pass to every receiver and tight end who was active Sunday, and connected with Riley Cooper for more yards than Cooper had in his first five games combined. It might have helped that Tampa Bay played so much zone coverage, but Kelly said there was no difference in the Eagles' game plan from the previous game.
"We ran the same offense, did the same things," he said. "Riley's been open a lot. We just haven't thrown the ball to him."
One of Cooper's catches went for a 47-yard touchdown. Kelly praised Foles' deep ball, which was inconsistent last season. Foles seldom threw the ball deep in his previous appearances in Kelly's offense, but that's the first drill the Eagles do at the beginning of practice.
Foles' decision-making was adept Sunday, and the team has confidence that he can be a starter. Whether he will start against the Cowboys depends on how quickly Vick recovers. Kelly eventually will be forced to make a decision, but he has not been shy about his confidence in both quarterbacks.
"I know a lot of people, when your No. 1 quarterback goes down, there's a very big drop-off," Kelly said, "and there was no drop-off for us at all."