Niebla, 49, has been Cleveland’s assistant pitching coach for the last two seasons.
He is widely credited with helping develop starters such as Shane Bieber, former Padres farmhand Corey Kluber, Mike Clevinger — who’s now with San Diego — Trevor Bauer, Triston McKenzie, Aaron Civale, James Karinchak and Zach Plesac.
Preller is still interviewing candidates to replace manager Jayce Tingler, who was fired on Oct.
“Most managers today, they’re just looking for really quality people they can surround themselves with.
“That as a part of the whole deal.
The Padres beefed up their rotation last offseason, only to watch several starters struggle to go deep in games.