https://www.nhl.com/news/2017-18-capitals-breakdown-key-factors/c-290773714
There's not much left in free agency, though, esp. at LD after Beauchemin returned to the Ducks. Stuart, Kindl, Liles and Tyutin don't offer anything more than Orpik and maybe not even anything more than Chorney at this point. Franson could be interesting I guess but I assume he's going to want a contract over a PTO and they might as well go with Bowey at 3RD anyway. It's Djoos/2LD that figures to be the bigger question mark. I'd look more toward the waiver wire for defensive depth if needed, though. There may be some decent options at the end of the pre-season and as-is they have enough prospects to battle it out internally over some slower stopgap vet.
Between existing depth forwards, I wouldn't be against adding a depth forward PTO. That may not be a priority at all but more competition beyond the Hershey options would be a good thing. I'm not sure Graovac, Boyd, Barber and O'Brien present enough of a challenge for Walker, Smith-Pelly and Stephenson. Plus, there's a bit more quality remaining among unsigned forwards between Jagr, Vanek, Iginla, Gionta, Upshall, Winnik, Chiasson, Hudler and Da Costa. Hard to say which of those will accept PTOs, though, and for a lot of reasons we can scratch off Jagr at least.