Clayton Kershaw was called up to the Show in 2008 at the age of 20. In 107 IP, he allowed 109 hits, struck out 100, with a 4.26 ERA and a 1.495 WHIP. Of course, he went on to build a Hall-of-Fame Career!
Julio Urias was called up to the Show in 2016 at the age of 19. In 77 IP he allowed 81 hits, struck out 84, with a 3.39 ERA and a 1.455 WHIP. Now, after injury and other BS, he is 23 years old and finally ready to take up where he left off.
Julio Urias has pitched parts of 4 seasons in the Bigs, where he has a 3.