Colts linebacker D'Qwell Jackson and cornerback Darius Butler started this week preparing to face Robert Griffin III.

So much for that.

After Washington Redskins coach Jay Gruden announced he was making a quarterback change Wednesday, both players started cramming for Colt McCoy. The actual transition began when word first leaked Tuesday that a move could be coming, turning what is a holiday week for most of America into one filled with overtime for the Indianapolis defense.

"Before I stepped foot in here today, I had watched their last five games — RG3 had started three of the five and Colt started the other two," Jackson said. "Now I've gone back and put the Dallas game on my iPad and some of the preseason games he played in."

Jackson already has some working knowledge of McCoy, who was his teammate for three seasons in Cleveland, and the Colts (7-4) had already done most of their prep work dissecting Gruden's offense before the announcement.

There are still plenty of bugs to work out.

Griffin, the 2012 NFL Offensive Rookie of the Year, produced his best results when he could move around effectively. He hasn't been nearly as good in that area since tearing the ACL in his right knee at the end of the 2012 season, and he's 0-3 since trying to return from a dislocated left ankle this season.

The Colts have detected a similar style from McCoy — and better results.

"Right now I believe Colt McCoy is more agile than RG3," defensive tackle Ricky Jean Francois said Wednesday. "It's really no different. We're preparing for Gruden's offense, not necessarily one player or the other."

Simulating the mobility of Griffin or McCoy might not be easy, either, with 16-year veteran Matt Hasselbeck running Indy's scout team. Another potential problem is injuries.

The Colts practiced Wednesday without either of their starting cornerbacks, Vontae Davis (right foot) and Greg Toler (concussion). The Colts also were missing backup defensive backs Colt Anderson (knee), Josh Gordy (lower back) and Loucheiz Purifoy (concussion), linebacker Andy Studebaker (hamstring) and Jackson, who got his customary extra day of rest.

Coach Chuck Pagano expects Indy to be closer to full strength when the Redskins (3-8) arrive, saying he expects Davis and Jackson will play Sunday and that Toler, Purifoy and Gordy could return to practice Thursday.

But there are plenty of other nuances and tendencies to break down between now and Sunday, and all of it requires extra time.

"There's a little more work, but it's not like you're going from RG3 to Peyton Manning, a pro-style type of guy," Butler said. "Colt McCoy can still move around pretty well, so it works out for us."

Nobody in the Colts' locker room understands the challenges McCoy poses better than Jackson, who saw it firsthand.

"The toughest thing is to make sure he's in the pocket," Jackson said. "He's a smart guy, a capable guy who has weapons around him. We've got to make sure we stop run and keep Colt in the pocket because he can extend plays."

NOTES: Pagano said tight end Dwayne Allen is listed as day-to-day with an ankle injury and right guard Hugh Thornton also missed practice with a knee injury. Right tackle Gosder Cherilus (shoulder) returned to practice, but backup offensive lineman Xavier Nixon did not finish practice because of a foot injury. ... Without Thornton, Pagano said Joe Reitz, who started at right tackle last weekend, and Nixon split most of the plays with the starters Wednesday.