MUT Hero NaVorro Bowman question

My current MLBs are 87 OVR Tier 3 NaVorro and 86 OVR GOAT Ray Lewis. I'm currently working on getting the 91 OVR MUT Hero version of NaVorro, it will probably cost me ~275k and I should have it within a few days. Now to the question. Do I:

1. Keep the 91 OVR, discard the 87 into an Elite Token

2. Upgrade the 91 OVR w/ the 87 to the Tier 4 92 OVR with the unfakable chem/ability

3. Sell it for about ~355k and make a 50k or so profit.

My only concern is that I upgrade it to Tier 4 and eventually get a better MLB, and I won't be able to sell him. He'll be good for a while though and definitely will be a #2 MLB if I ever get a better one. What are your thoughts?