Grant, 24, spent this season with the Penguins' American Hockey League affiliate, the Wilkes-Barre/Scranton Penguins, and had four goals and 20 points in 46 regular-season games, and four points in 13 playoff games.
A 2007 fourth-round pick, Grant has spent the past four seasons in the minor leagues, with Wilkes-Barre/Scranton and the Wheeling Nailers of the ECHL. He can become a restricted free agent July 5.
Zolnierczyk, 25, split this season between the Philadelphia Flyers and the Ducks. He had one assist and 36 penalty minutes in seven games with the Flyers, and served a four-game suspension in March for an elbowing incident. He had 17 points in 52 games with their AHL affiliate, the Adirondack Phantoms. He was dealt to the Ducks on April 1, and had two goals in nine games with their AHL team, the Norfolk Admirals.
In 44 NHL games the past two seasons, Zolnierczyk has three goals, four assists and 71 penalty minutes.