We just move Sceviour to the fourth line and then let him walk at free agency for a big pay day.
Even without Nuke, there won't be enough spaces for Sceviour on the 4th line plus Ritchie still in the lineup. Patrick Eaves was playing better than even Sceviour, and he'll be returning likely in about a month ... maybe sooner. Coaches rarely allow an injury to lose a guys spot so he'll get a look when he comes back. It'd be great to see Ritchie hang on until that point, but he's likely immediately back to the AHL when Eaves is ready. They'd go with Eaves, Garbutt, Hemsky and Sceviour as the RWs.
Hopefully they don't go back to the Horcoff-Fiddler-Moen line when Horcoff is healthy. Moen's played well, but he's clearly not better than Ritchie already is. Horcoff-Fiddler-Sceviour were good together, and Ritchie could be even better with that line as we've seen. That could buy Ritchie some extra time for the moment.
Assuming everyone is healthy, and since Nuke won't be back likely until May based on Klingberg's time frame ... LWs look pretty set with Benn, Cole, Horcoff, and Roussel with Moen as the extra forward.
There's too big of a risk of injury IMO to trade Sceviour in order to make space for Ritchie full time right now. The team overall is better off just using Ritchie's waiver exemption for the moment. They won't stay completely healthy, and you'll be pretty upset that you traded a needed depth piece. Instead you could keep both players fresh and ready by sticking likely short term with Ritchie in the AHL and Sceviour in the NHL. That way when an injury hits there's not adjustment for Sceviour to come in cold after mostly siting for several weeks.
You're probably talking a month at most from when Eaves was healthy to the playoffs. They could then bring Ritchie back up the final couple weeks before the playoffs like they did with Nemeth.
That depth was important last year when you had Cole and Dilon out in the playoffs and just before fighting to get in. Really there's no reasonable justification to start picking yourself apart given they position they've climbed back into. If they slip again though ... you probably don't need to be as cautious with the depth.
You're in a perfect situation where you have a LW (McKenzie), C (Morin), RW (Ritchie), and D (Jokipakka) to come up for a specific position.