"Some of the guys who are coming back, I'm comfortable with," Mattingly said Monday at his introductory news conference. "I think it's important to the continuity."
Mattingly, Miami's eighth different manager since 2010, has the task of creating a stable environment for a franchise that has had high turnover.
• Mattingly: "I hope it will be 10" years with Marlins
The Marlins haven't announced their staff, but Hill, Cornelius and Harris are under contract through 2016. Menechino, Miami's hitting coach the past two seasons, is projected to return once his contract is finalized.
Wallach would be an addition.
"We think Tim Wallach is going to come with me as the bench coach, and a number of guys are coming back," Mattingly said. "I pretty much talked or texted with every coach on the staff."
Wallach's status is linked to the ongoing Dodgers managerial search. If Wallach isn't named manager, he plans to join Mattingly in Miami.
Barring anything unforeseen regarding Menechino, that will leave the pitching and outfield/third-base coaching positions to fill.
Brett Butler, the outfield coach the past two seasons, will not return. And it is unclear if Chuck Hernandez, the pitching coach the past three seasons, will be back.
Dodgers pitching coach Rick Honeycutt could be a pitching-coach possibility if he doesn't stay with the Dodgers.
Wallach, a five-time All-Star during his 17-year big league playing career -- 13 of those with the Expos -- was Mattingly's third-base coach from 2011-13 and his bench coach the past two seasons.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.