I like Diggs, but the worrisome thing is that he's done this through 4 games every year, and failed to continue it every year, yet he is still being moved right now at strong WR1 prices.
Here is his pace through 4 games each of his seasons so far:
2015: 100 rec, 1676 yards
2016: 100 rec, 1488 yards
2017: 88 rec, 1564 yards
Obviously he failed to continue that pace each of the previous two years. He certainly looks the part, and injuries probably played a role in that, but people seem to be wowed by this start this year thinking it solidifies him as a strong WR1. However, the reality is it's not even his best 4 game start and he has a history of fading after 4 games.
CJA is very much the same. With both guys there is a legitimate concern that they are just in the first step of the same trend they've repeated so many times before (starting strong, then fading) that does not really seem like it is getting factored into their value.