The 23-year-old Leone was 1-1 with a 4.58 ERA with 17 strikeouts and four walks in 17 games in Mobile.
He appeared in one game for the Diamondbacks after being acquired June 3 as part of the trade that sent outfielder Mark Trumbo to Seattle and brought catcher Welington Castillo to Arizona. Last season, his first in the majors, Leone was 8-2 with a 2.17 ERA with the Mariners, striking out 70 in 50 games.
Dorn's latest stint with the Diamondbacks was brief. He was recalled from Reno on Sunday. He is hitting .434 for the Aces but just .167 (5-for-30) in 23 games with the Diamondbacks.