Rasmus Sandin: Will turn 23 next week. Played in 52 regular season games for Toronto so far this season, so fair to say he's basically been a full-time defenseman. Generally has played 15-19 minutes per game, so not a first pairing defenseman; probably sort of a 2nd pair for Toronto. BUT this may be his first full-time season, so not a surprise - maybe more of a surprise that he is at least marginally a top 4 defenseman at age 22. 5'11", 185 lbs., so a bit undersized, but interestingly, with Hathaway gone, he comes in as #3 on the Capitals in hits for the season, with 113, so he seems not to be afraid to mix it up a bit. +/- of +10, for what that's worth.
The Caps will have several years of control and reasonable cost containment over him, so there's that.