Bulls are not very good outside of Rose. Rose has probably another month or 2 max before people start wondering how long term this "new" Rose will be. You can't sit out an entire year and them come back and waste another year due to "rust".
Regardless of him sitting out last season or not, he would still not be back to pre-injury form.
When a NBA player tears an ACL, it takes them about two years to fully recover.....
if they ever fully recover. Just look back to when CP3 tore his MCL. He had spurts where he resembled his pre-injury form, but he did not fully reach that point until a couple years afterwards.
It's gonna take time, man. Unfortunately, our FO have yet to add a #2 consistent scorer to this team. If (for example) D-Wade was coming back from an ACL like Rose, Miami would be well-equipped to handle his "rust". Why?.....Because they actually have other players capable of creating offense. The Bulls don't have that luxury.
The Bulls are expecting Rose to knock off "rust" while relying on Butler, Deng, Noah, or Boozer to create offense. None of those players are capable of doing it. I love Jimmy Buckets, but he's basically the same player as Luol Deng, which is why Deng should have been traded last season for an offensive creator at SG & Buckets should have slid over as the starting SF.