Because Jason Kelce missed a few weeks in training camp after a minor elbow surgery, rookie Cam Jurgens got a ton of chances with the Eagles’ first-team offense in training camp. Offensive line coach Jeff Stoutland called those reps “irreplaceable.” But it did slow down Jurgens’ development in another area. Stoutland wanted the second-round pick from Nebraska to get some training camp reps at guard but that couldn’t happen because Jurgens spent most of his summer next to Landon Dickerson and Isaac Seumalo with the first-team offense. “Couldn’t do that because Kelce was (injured),” Stoutland said. “That took that out. That’s not done yet. I think you have to play…