I'm more okay with this prediction more so than the OP's either Sweeney OR Knox. No doubt they're hard not too root for and get excited about. But I'm trying to temper expectations.
What's a successful season for either of these guys statistically? Rec's, Yards, TD's?
Our leading TE last year was Croom with 22 receptions, 250 yards and 1 TD. Go ahead and add in Clay's statistics (21, 184, 0) to form a total and you get a whopping 43 receptions, 434 yards and a TD. That is less than average as far as the league goes...collectively! Let's stop comparing our current players to past players, and start looking at them in comparison to players across the league:
If either player totals this amount of yards or receptions as last years COMBINED total, you can certainly count it a success. A rookie TE with these stats (43, 434, 1) would be encouraging. But keep some perspective. If you compare this stat line to last years TE crop across the league, we'd collectively finish 19th in yards, right ahead of Jesse James but behind C.J. Uzomah (43, 439, 3).