Andre Dillard had been a left tackle since he was 14 years old. Until this week.

The Eagles’ first-round rookie is set to make his first start as a right tackle in place of two-time Pro Bowler Lane Johnson. Johnson sustained a concussion Sunday in the Eagles’ loss to New England and has been ruled out for the Seahawks game on Friday.

Dillard started three games at left tackle earlier this season when Jason Peters was out with a knee injury and made the switch in practice this week. It’s a big transition, and Dillard didn’t sugarcoat it.

“Say you all of a sudden had to write a big essay with your left hand right now,” Dillard said. “You think about how that would feel. It’s kind of like that. ... Your brain kind of acts like a muscle in this case. If you do one thing in one way for 10 years like I have, then everything about you is geared toward that. If you flip it, your brain is kind of like, ‘Whoa.' "

Dillard said he’d never played right tackle for more than a few snaps in practice before this week. The Eagles gave him some reps during training camp at Johnson’s spot, but the Eagles drafted him to eventually succeed the 37-year-old Peters, so he’s spent most of his time on the quarterback’s blindside.

While it’s a challenge, Dillard said he’s made strides this week in practice.

“It’s going as smooth as it can be,” he said after Friday’s practice. “It’s obviously going to be a challenge, but I’m up for it and I’m perfectly capable. ... This week’s been a good week of preparation.”

Johnson left last week’s game in the second quarter and was replaced by Halapoulivaati Vaitai. Coach Doug Pederson said he didn’t want to call on Dillard without giving him a chance to practice on the opposite side, but the week of practice has granted the team the luxury of returning Vaitai to his role as a backup swing tackle.

“He looks good,” Pederson said of Dillard on Friday. “Each day, he’s gotten better. He’s really settled in and had a good day yesterday. Expect the same today."

Greg Ward gets back under center

Replicating Russell Wilson is a tall task for anyone, especially for a 40-year-old.

The Eagles used multiple players to impersonate the Seahawks star in practice, but it’s safe to say Josh McCown doesn’t exactly capture Wilson’s athleticism. Nate Sudfeld and his 4.93-second 40-yard time likely had a tough time, as well. When the Eagles needed to simulate Wilson’s ability to escape the pocket, they turned to practice-squad receiver Greg Ward.

The 24-year-old converted to wideout after finishing a dominant college career as Houston’s quarterback. In his final two college seasons, Ward threw for 6,384 yards and rushed for 1,632.

“It was pretty fun, reminded me of my old days,” Ward said. “I was trying to make some plays and give my defense a good look.”