Nearly a year ago, the personnel was in place for the Ravens to make a deep push into the NFL playoffs. The roster hasn’t changed much since then, but there are a lot of questions concerning top players returning from injuries and several young ones who could make significant impacts. That should make training camp, which begins in a little less than a month, very interesting. “We’ve got a lot of work to do, obviously in all areas,” coach John Harbaugh said. So today, we’ll take a look at some of the top positional battles of training camp, which begins July 27 with a full-field practice for rookies and veterans: Running back If both perform up to par, then third-year player J.K.