No matter if you're optimistic or pessimistic about the upcoming Bengals' season, it's almost a given that you think the key to the season will be the offensive line. If the offensive line plays well as a unit, it's almost impossible to imagine the offense not being a top ten type. If the offensive line plays poorly, it's almost impossible to imagine the team winning seven games.
With this being the case, Reggie Kelly is a monstrous loss. Sure, he's a tight end, and is fairly anonymous around the league. He would have been by far the worst receiving tight end to make the roster. However, it cannot possibly be understated how important he was to the offensive line as a whole. Eventually, Whitworth or Smith/Collins are going to be overwhelmed by a pass rusher. Reggie Kelly would have lined up on their side and taken care of it. He's solid at the point of attack as a run blocker. Outside of Carson, he's probably the most important offensive leader.
Hopefully I'm overestimating how much Kelly means to the offense. I fear that I'm not.