PHILADELPHIA (973espn.com) — The Eagles' most talented cornerback returned to the field after missing half the season with a dislocated ankle Sunday night in Dallas and held up better than anyone could have expected.

Including defensive coordinator Jim Schwartz, who admitted he really didn't know what he was going to get from Ronald Darby, who toiled in just 18 snaps before going down during the season-opening win at Washington.

"I couldn't tell you with 100 percent accuracy if he was going to be able to play 10 plays, or if he was going to play the entire game," Schwartz admitted earlier this week.

That uncertainty played into where Darby lined up -- at right cornerback. Prior to the injury, the Florida State product was on the left side and Jalen Mills handled RC with Patrick Robinson in the slot. On Sunday in Dallas, Darby was put on the right side with Mills handling LC, something he did throughout Darby's absence.

Moving forward it might remain that way or it might not.

Darby himself admitted he threw up at practice on occasion trying to ramp up his conditioning which fell behind during the three weeks he spent with a protective boot and was jetting around the NovaCare Complex on a scooter to protect his damaged right ankle.

So Schwartz went into the Cowboys' game planning to rotate in rookie Rasul Douglas at times, something that ultimately wasn't needed as Darby was able to play all 63 defensive snaps in an effective fashion.

"We were prepared to rotate if we had to and give [Darby] a breather, but every time we checked on him, he was ready to go, and he was playing good, consistent football," Schwartz said.

Because Douglas can't play the left side at this stage, Schwartz decided to keep Mills on the left side (generally where any team's best corner is placed) in case the rotation was needed.

Whether it stays that way against Chicago is up for debate.

"I don't know," Schwartz answered when asked if Darby will be staying on the right side for now. "I don't want to commit to anything right now. We'll see how it plays out. I like both players' flexibility to play both sides."

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen