Kelly's quarterback plans have been thrown into disarray this season, with rookie Matt Barkley being forced to play in last Sunday's 15-7 defeat to the New York Giants due to injuries to both Michael Vick and Nick Foles.
Foles has already been confirmed as the starting quarterback for Sunday's match against the Oakland Raiders having recovered from concussion, but Kelly refused to elaborate on whether he would remain first choice once Vick returns to full fitness.
"I am going to make the determination who our quarterback is on a weekly basis, first and foremost based on health," Kelly said.
"In the ideal world, Mike's the healthiest in the world, Nick's the healthiest in the world, Matt's the healthiest in the world. Let's get to that point and we'll have a conversation.
"I'm getting ready to play the Oakland Raiders and I'm getting ready with Nick Foles and Matt, because Mike's not practising today. And that's it. It doesn't help me or anybody to say, 'Hey, next week, when Mike comes back, what are we going to do?' Because what if next week, Nick and Matt are hurt? I don't know."
The Eagles are currently second in the NFC East with a 3-5 record having lost their last two matches.