They could, but I'd prefer they pull another Vella. Get an OA for a 4th-5th round pick to be there to back up, spell Cavallin and use that Import pick on a forward. Preferably a 17yo so they don't leave the same year as Koly but picking an 18yo NHL drafted prospect would be safer. Or so the theory goes if BB isn't your GM.
There aren't really too many OA goalies out there.
Popovich in Guelph maybe, but Guelph may also decide to trade Daws instead. Popovich may also be somewhat expensive, since he was pretty good this year for them.
Colton Incze in Windsor, but he was also not very good as soon as he got to Windsor, and I don't imagine it'll be any easier for him in Flint next year. He'd be cheap though.
Bonello in Kingston wouldn't be too bad, since he knows what it's like to have to go up against a ton of shots, but Kingston may decide to keep him too unless they really like Dugas and Frappier (or a prospect). He too would likely be pretty cheap.
Propp in North Bay, same situation as Popovich in Guelph. He was good for North Bay, so they may decide to deal Purboo instead to open up a spot for Vrbetic.
McGrath in Niagara, but he's sucked there and he doesn't even have the excuse of playing on a crap team. He may just be released altogether and Niagara just trades for a better goalie to replace Dhillon.
Nick Donofrio. Same as McGrath, but Hamilton was worse than Niagara. Still, not really an excuse for him. He was bad last year, but at least he'd be cheap if you decided to go for him.
Richardson in Kitchener. I'd expect them to keep him.
So really your best shot at an OA goalie is for North Bay, Kingston or Guelph to move on from theirs and trust their 00'/01' backups instead. Otherwise, you essentially are just taking a chance on a struggling OA goalie like Incze, McGrath or Donofrio instead.
My personal opinion would to give Linton a serious look as the backup and start planning on life after Cavallin. I'd give Cavallin one more season as the starter but if he can't hack it by then, then it may be time to look at Linton as the goalie of the future and to give him serious reps as soon as this season.