If they were down in England they'd have the resources to strengthen, but at the moment their playing squad is Championship standard.
I'm not saying they'd be a very good premier league team, but they would definitely be able to stay in the bottom half of the table. They have some depth, but you don't need alot of depth if you don't have europe anyways.Personally I think they would finish bottom half of the premier and very possibly bottom 6. They have little strength in depth and probably couldn't cope with the intensity of our league. Not being funny but Celtic v Kilmarnock isn't exactly a toughie. They rest players all the time as they know that even a 2nd string team is good enough to beat most teams in their league.
In the champions league City drew them twice, we were able to beat Barcelona but not Celtic, and Celtic were the team that halted our 10 game run.