The consensus timetable for the return of Philadelphia Eagles quarterback Carson Wentz, who suffered a torn ACL in Week 14, has the MVP candidate on track for a potential Week One appearance in 2018.

One orthopedic surgeon, however, thinks an Opening Day return is "very, very optimistic" and that Philadelphia has reason to worry about its quarterback's knee.

Joining Angelo Cataldi on SportsRadio 94 WIP this week, Dr. John Kelly, a professor of clinical orthopaedic surgery at Penn Medicine (University of Pennsylvania), said Wentz's injury is actually "an RG3 equivalent" -- a reference to the battered former Washington Redskins quarterback, Robert Griffin III, whose career lasted all of five seasons.

"This is an ACL, plus at least two ligaments," Kelly said. "This is an RG3 equivalent, folks. This is worrisome ... That's a long rehab. And if it were my patient, it would take nine, 10, 11 months."

The surgeon then went on to say, at least from his perspective, that it's "absolutely" too optimistic to expect Wentz back on the field for the Eagles' Sept. 6 opener. In his eyes, the two-year veteran would need a minimum of nine months of rehabilitation to start playing -- with a knee brace, no less. And that kind of time frame suggests Wentz wouldn't be available until mid- to late-September at the earliest.

Kelly's comments, while prominent, were also sandwiched between jokes -- the 94 WIP team even openly identified the doctor as a "stand-up comedian" during the discussion. And the surgeon, who specializes in shoulder operations at Penn Medicine, often followed his opinions, formed from the same video of Wentz's injury that's available to the public, by deferring to Dr. James Bradley, the man behind Wentz's ACL surgery.

If anything's clear from his comments, however, it's this: No one truly knows just when Carson Wentz will be ready.