Kelly began the season with Michael Vick as his number one choice, but a series of injuries to the veteran has opened the door for Nick Foles to stake his claim for a starting role.
Foles has thrown 16 touchdown passes without an interception this season, including 10 in his last two games, but Kelly is adamant that he will not make his decision until Vick returns to full fitness.
"When that day comes, we'll have a discussion. That day's not here. It's who's up, who's available," Kelly told reporters.
"I've had guys go down on Friday, so why does it really matter who I say is the starter for the next Sunday's game?"
Foles will take the fist-team practice reps today and is expected to retain his spot in the starting lineup for Sunday's match against NFC East rivals the Washington Redskins.