No, we can't franchise Suh. He's already on his third contract.
However, based on the Geno Atkins deal and based on how Suh determined to come to LA, if we win it all (which I truly think is a strong possibility), then unless he drops 15+ sacks and has numbers he's never had before, he is basically at his going rate at $14M/yr and with the cap monsters the Rams have, they might be able to work out a deal with him.
Let's just say that if the Rams entertained even the notion of acquiring Mack knowing his price tag, they can probably figure out Suh.
One thing about their plan is that they may be waiting for the new CBA for Goff's contract. The CBA ends in 2020 and that's Goff's option year.
they may want to franchise him OR they may want to try and sell that he could get more money under any new CBA and have them wait.
If any extension doesn't materially affect Goff's 2020 cap hit, then there's a possibility they could put together a two year deal for Suh covering 2019 and 2020.
Too many variables to consider at this point, but we do know is that it's not a fait d'accompli that Suh is only here for one year.
Who knows, maybe he can open up a rehab facility next to the Rams' facility...