Just as Barry Trotz has visions of multiple forward line combinations dancing in his head, Capitals assistant coach Todd Reirden has a variety of defensive pairings he’d like to see once training camp rolls around in September. “It’s going to be a competitive situation,” Reirden said last week as the Capitals’ development camp drew to a close. “We have to see what pairs work well when we get them together. “Obviously, [John] Carlson and [Karl] Alzner have spent a lot of time playing together in the past and I know [Brooks] Orpik and [Matt] Niskanen have played together in the past. “The logic would be to go right away to something that’s comfortable, but I think it’s more important to switch them up and let them learn together and help them grow as teammates, especially early on. “So we’ll try some different looks in the beginning of training camp, moreso than when we get closer to the end. It’ll be a good competition. We’ve got some good players back there and some good depth and I’m looking forward to getting it going. I’ll be anxiously awaiting rookie camp and training camp.” Back on July 1, after he signed Orpik and Niskanen to a combined 12 years and $67.75 million, Caps GM Brian MacLellan said he envisioned right-handers Carlson, Niskanen and Mike Green staying on their strong sides. He also mentioned the familiarity Orpik has with Carlson after being paired together with the U.S. Olympic team.