Where are the Bruins going to get a top 3D making around $4M to make that top pair make less than $5M (McAvoy makes $916,667)? If the Bruins hypothetically get a defenseman to play with McAvoy, and Krug is pushed to the bottom-pairing, I hope Krug is utilized to his strengths. I just think Krug deserves to play higher up in the line up and be paired with someone better than Kevan Miller or McQuaid.
I was for signing Alzner in the offseason a few months ago but with there being very little quality FA defensemen out there, he's going to get a long term deal at a high cap hit which I think the Bruins should stay away from. Here are some good pros and cons to adding Alzner from a TML perspective (
https://theleafsnation.com/2017/03/31/this-is-absolutely-not-how-the-leafs-will-look-next-year/).
Orlov could be an interesting option, but I'm not so sure he would be able to handle 20+ minutes a night on the top-pairing.
I don't think Dumoulin is good enough for top-pairing minutes. He is more of a middle-pairing defenseman.
de Haan has potential, but I'm also not sure if he could be depended on to play on the Bruins' top pair. If someone that has watched him more can fill me in that would be great.
I think MIN protects Scandella.
Muzzin would be an interesting option, but LAK is lacking a lot of talent at LD so they will probably protect him.
Jack Johnson isn't good enough to handle top-pairing minutes. Ian Cole and Jon Merrill too.
Noah Hanifin is probably the most attractive option at defense for the Bruins to pursue, but Carolina would most likely want Pastrnak in return which the Bruins do not do.
Long story short, the Bruins need a top 3 LD, and it's been a need for a while. With that said, unless a team who has someone like Lindholm available due to the expansion draft and wouldn't mind a king's ransom of picks and prospects, I would prefer the Bruins stay put on defense. There's no need to sign or trade for a bottom-pairing LD when the Bruins already have options there (Zboril/Lauzon/Grzelcyk/O'Gara/Morrow/etc.). That's why I think it is more likely to target a 2nd line LW to improve the roster:
Marchand - Bergeron - Bjork
Trade - Krejci - Pastrnak
DeBrusk - JFK - Backes
Kuraly - Nash - Acciari
Krug - McAvoy
Chara - Carlo
Prospect - Kevan Miller/McQuaid