Despite the avalanche of injuries and corresponding roster moves in recent weeks, management has resisted promoting De Leon, the 24-year-old ranked as the club's No. 2 prospect by MLBPipeline.com. Calling him up for a spot start and sending him back down would have burned an entire option year, which is the most likely reason he hasn't been promoted yet.
In 15 starts this year at OKC, De Leon is 6-1 with a 2.86 ERA, a 0.979 WHIP and 98 strikeouts in 78 2/3 innings.
As for Maeda, he will be pitching on five days' rest and the Dodgers have maneuvered his rest to replicate his routine in Japan.