Quoting: steveospeak
Don't see any incentive for Vegas to do this type of deal. Yes they need picks and they may eventually move Miller, but he's got 3 years of team control left at a cheap rate, they are only going to move him now for a big return. Especially since he is one of the few RH defensemen in their system.
These stats don't paste right, so look at them here:
https://www.hockey-reference.com/players/m/milleco02.html
SUMMARY
2016-17
Career
GP
61
103
G
6
9
A
7
20
PTS
13
29
+/-
0
0
PS
3.3
5.8
PIM
55
94
SH
85
144
GWG
0
0
TOI
15:49
15:48
CF%
60.3
56.9
oZS%
64.8
65.0
You keep talking up Colin Miller like he's Seth Jones. He starts two out of three shifts in the offensive zone, and still, 40% of the shots on goal in his shifts go against him. When he's on the ice, shots on goal are 5% worse for Boston than with an average player. He plays fifteen minutes a night, which is 6th/7th defenseman territory. Usually when people have to play more minutes, they make even more mistakes. His plus minus is even, even when two thirds of his shifts start in the offensive zone. Miller pretty much stinks.
He's got some potential, and maybe in even fewer minutes, with a solid checker like Brooks Orpik to babysit him, he could keep the Caps from needing to rush the development of a future top four player like Madison Bowey, or a younger, even more questionable defenseman like Tyler Lewington. Miller fits the Caps needs because he's right handed, and because they've said they're looking to get younger and faster. Otherwise, his possession numbers are terrible, and they could probably get a cheaper deal with Roman Polak, whose corsi is three to four percent better than his zone starts, and whose name would lead to endless awful puns, if he's paired with Christian Djoos:
https://www.hockey-reference.com/players/p/polakro01.html.
Meanwhile, Vegas has ten defensemen on NHL contracts, and they'll probably start the season with seven. So they're looking to trade three. Miller was picked in the 5th round by LA, traded to Boston after a decent year in the AHL, when he still didn't fit into LA's plans, stuck in the AHL for another year, where he made the all star team and won a big one-way contract based on almost no NHL experience, and.... exposed to the expansion draft because his performance relative to the first year of that contract did not make him a very significant asset. I think the Caps offer a 4th for him, and maybe a prospect on a two-way contract whom the Caps see as a spare part, but who will get great opportunities on an expansion club that currently only has two players on two way deals, both of whom are NHL ready.