ASHBURN, Va. -- Washington Redskins quarterback Robert Griffin III's recovery period was made a little clearer Wednesday, putting a possible return at around eight weeks.

Robert Griffin III is expected to miss around eight weeks, according to Redskins coach Jay Gruden. Patrick Smith/Getty Images

Coach Jay Gruden said the third-year quarterback will be in a cast for the next 10 days, after which he'll likely spend four to six weeks rehabilitating his dislocated left ankle.

Griffin suffered the injury in the first quarter of Sunday's 41-10 win over Jacksonville. Initial fears of a possible fracture were dismissed Monday, and he required no surgery.

Kirk Cousins will start in place of Griffin, and when asked what would happen if he was playing well upon Griffin's return, Gruden said they'll worry about that later.

"Right now, we're going to prepare with Kirk Cousins as our starter and Robert's going to rehab, and all decisions after that will come after that," Gruden said. "But right now, we're going to go try to do the best we can and get Kirk ready to go and beat Philadelphia."

In the 31 games he has started, Griffin has left four with an injury. Cousins took over for him at the end of last season, although that occurred when then-coach Mike Shanahan shut Griffin down for the season to make sure he was healthy for the offseason.