"I told Brad his role will change now," Jennings said.
Andre Rienzo, called up from Triple-A New Orleans to fill Cishek's roster spot, takes over as long reliever.
"Now, with Brad it gives us that second left-hander we can go to, maybe in matchup situations," Jennings said. "We'll get him in spots to give us maybe that inning instead of being a long guy."
Hand, 25, is 1-2 with a 5.36 ERA in 26 games, with three starts this season.
Out of options, Hand made the Opening Day roster, but he has been asked to take on multiple roles. As a long reliever, he'd go through extended periods between appearances.
The Marlins have explored trade options for Hand, and a few weeks ago, had advanced discussions with the Blue Jays. But return compensation couldn't be agreed upon, and nothing materialized. Now it appears he will stay with Miami, but in a more specialist capacity.
Hand broke in with the Marlins in 2011, and he had been competing for rotation spots every season. Now, it appears his future with the club could be in the bullpen.
"Brad has been in so many different roles this year, starting, he's been in long relief," Jennings said. "He's been in to face one [batter]. He's been in complete innings. I think the versatility he's shown has helped build his confidence in a good way. It's good because we're going to be counting on him to fill some different spots.
"Basically we've had Dunn all year with Brad either starting or in the long spot. It will help Chuck and I when we have to make decisions on matchups or what we need to do, should we double-switch or go with a straight-up switch. Having Brad now in different roles will be big for us."
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.