Coburn's left eye was swollen shut after a deflected puck hit him early in the Flyers' 4-2 loss at Pittsburgh on Sunday. There was no structural damage to his face, but the blow opened a cut that required over 50 stitches to close.
The Flyers sent Coburn to an ophthalmologist on Monday for tests.
"Everything checked out OK," Flyers general manager Paul Holmgren said in a statement. "The only issue now is the swelling around his eye. That is the concern we have right now moving forward. Everything in and around his eye is fine. That's good news.
"He will still be listed as doubtful for the game [Tuesday]."
Holmgren said Coburn's flight home Sunday night was quite unpleasant. The defenseman had lightheadedness and vomited, but had gotten over that by Monday.
If Coburn can't go in Game 3, when Philadelphia will try to avoid dropping into an 0-3 hole, Ryan Parent is expected to take his place in the lineup. Parent is a speedy defenseman who played 22 regular-season games and dressed for the playoff opener at Washington.
"I was hoping he was OK, but in the back of your mind you know you have to be ready," the calm, 21-year-old Parent said. "It's part of my personality. I don't really get excited about too much."
Coburn's injury is just the latest blow to the Flyers' defense corps. Philadelphia lost top defenseman Kimmo Timonen on the eve of the series against the Penguins because of a blood clot on his ankle.
Without Timonen and Coburn, the Flyers are without two key players who not only defend well but also help on the power play and the transition game to offense.
"Surprisingly, I don't feel that bad," said 35-year-old Derian Hatcher, who played 28½ minutes in Coburn's absence Sunday. "We will all do what we have to do back there. It's tough with
Kimmo being out, and if Cobey doesn't play, obviously it's going to be that much tougher."