Nielsen does not need to be protected, and definitely won't be protected.
We have two forward spots remaining after the obvious Larkin, Mantha, Bertuzzi, Fabbri, and Rasmussen. Yeah, Svechnikov and Timashov will be in the mix, but don't be surprised if Smith is there as well, by the end of next season. Either way, like I said, we won't be losing anything too significant.
I'd say worst case scenario, we lose a Lindstrom (3rd pair defenseman) or a Timashov (3rd line winger), and best case scenario, we give up a mid round pick to get them to take Nielsen... The latter is probably unlikely, but Seattle will be looking to take on some bad contracts to get to the cap floor. They can't build a team completely with players on entry level contracts...