Parker just needs to stay healthy and get fed the ball, he'll be fine. For example this season Michael Crabtree has 145 targets, 89 receptions, 1003 yards and 8 td's. DeMaryius Thomas 145 targets, 90 receptions, 1083 yards and 5 td's. Parker's two year total numbers are 141 targets, 82 receptions, 1238 yards and 7 td's. If Stills does leave in free agency as some have speculated Parker's season targets are going to greatly increase and his overall numbers will look just fine. I think if he can stay on the field and get between 140 and 150 targets per year he could put up Pro Bowl consideration like numbers.
Parker has been slowed a little by nagging injuries, but compared to his draft class he's doing great. Of the group of Amari Cooper, Kevin White, Jalen Strong, Breshard Perriman, Philip Dorsett, Nelson Agholor, Devin Smith and Dorial Green -Beckham only Cooper has been better than Parker and he's getting 130+ targets per year.