Trading Pettersson while retaining 750K is likely the best option to give the Penguins cap flexibility heading into the season. While some are worried about LD defensive depth, Rutta has played LD quite a bit from my understanding, and would very much fit the mold of what Petry wants in his defensive partner. DOC and Smith start in the minors due to their waiver eligibility, Zohorna and Nylander start in NHL because they will likely be claimed if waived, and Caggiula and Archibald get waived to WBS because they can likely sneak both of them through waivers.
Huge risk. What happens if Dumo doesn't rebound from last year and POJ isn't really ready? That happens and that left side is just trash.
POJ isn't ready, you have Ty Smith (who's played more games at the NHL level). This also gives them almost 2M in cap space, which is enough to pick up additional defense depth at the deadline.