Schultz is simply too small right now to be a big-time contributor. He needs at least a year in the weight room, and about 15-20 lbs. of added bulk to become a factor. He gets pushed into the backfield like he's on skates when blocking, and can't break tackles due to his light weight. The earliest we should start judging the value of the Schultz pick is this time next year. Keep in mind that he was the 137th pick in the draft. While technically he's a 4th round pick due to compensatory selections, in a 32 pick per round draft, he'd be the 9th pick in the 5th round. He's the equivalent of Matt Johnson in draft status.
Schultz is listed as 4th on the depth chart at TE, and will likely be inactive for all the games unless he can contribute on special teams. He has the frame to add bulk, and the potential to develop into a good player; but, that potential is at least a year away, if not two years. Schultz is also just a rookie, and the other 3 players have more developmental time on the roster.
There are still 2 weeks to go before the end of the preseason, and Gathers could make a late push for a roster spot. By all reports, he's very serious this year about becoming a better blocker. Right now, Swaim is the starter, and Jarwin looks to be a vital part of the passing offense. So, we'll see what happens.