Ready for a little hockey in the middle of July? The Caps host their annual development camp starting Sunday at Kettler Iceplex in Arlington. The organization’s top prospects and recent draft picks gather for a week of practices and scrimmages, hoping to make an impression on the coaching staff before training camp starts in September. Look out for defenseman John Carlson. The 19-year-old was the 27th overall pick in 2008, but had a dynamite year in juniors with the London Knights (16 G, 60 A) and when that season ended he appeared in 16 playoff games with AHL Hershey. Playing one step below the NHL, Carlson saw serious ice time for the Bears, who won the Calder Cup. With three Caps defensemen restricted free agents this summer — Shaone Morrisonn, Milan Jurcina and Jeff Schultz — Carlson’s presence provides security if contracts can’t be worked out to Washington’s satisfaction. Either way, the 6-foot-2, 218-pounder will be a factor at training camp.