Let's say the offense is good

Forget about W-L for a minute here. Let's say E and O keep to their word that they are going to stick to the passing game and we have a pretty dynamic passing game in which Joe Burrow shows off his arm and is really impressive. This year's QB class going into the NFL is quite honestly not very good, so it's not crazy to think that Joe Burrow could potentially be a mid-round pick if he has a good season (Danny Etling got drafted). So, let's say he does decide to enter for the draft. Who are our QBs? Brennan would be the clear front-runner to start as of right now, but who is backing up the 6'5 190lb QB? We have the two backup walkons (who I suspect O will award one of them with a scholly at some point). We have Peter Parrish coming in as a true freshman. After that, there's nothing. I could imagine O going out and getting another JUCO/Grad Transfer or even getting a transfer to come in this year and sit out the 2018 season to be eligible for 2019 to either add depth to the position or compete with Brennan for the job. Now, I realize none of this is in high likelihood, but I thought it was interesting to think about. Don't take this as a prediction that Joe Burrow is going to go pro after this year. Just a little what if scenario.

ETA: I originally said that Peter Parrish had a weak arm in this post because someone told me that and I hadn't actually seen him before. I watched a video of him and his arm strength is actually pretty solid. I was talking out of my arse a little there. My bad.