If you go to baseballsavant.com you can see player speeds from Statcast. He ran a 29.2 f/sec. on a steal of 2nd base. That's Billy Hamilton speed. 30+ is Buxton, Ichiro, young Billy Hamilton. J-Rod should definitely be updated to 88 speed. Also, he's projected to have the second highest WAR on the team. Guerrero and Franco had gold cards on their debut, how is Alberto Rodriguez got better stats than Julio Rodriguez on the same team? Julio should be a 77-79 silver to start. He also considered to have a very strong arm, good routes and doesn't make many errors. If you want to wait on the offense, it should have happened with Vlad and Wander, but even then he should still get credit for his defensive chops and his numbers for offense should be mid 60s to begin and vision at least in the 50s. I know he has to earn the diamond and gold, but anyone who has seen his minor league numbers knows he's a silver.
I'm pretty sure SDS takes speed ratings for live series cards straight off this list. When he is actually on the list his speed will be adjusted accordingly