The Grizzlies are preparing an offer sheet for Charlotte Bobcats restricted free agent Dante Cunningham, and team officials have held trade discussions with the Philadelphia 76ers as a response to forward Darrell Arthur’s season-ending Achilles injury.

Magnetic resonance imaging performed Monday on Arthur confirmed that he has a torn right Achilles and will miss the entire 2011-12 season. Memphis, shorthanded up front before Arthur’s injury, is in the market for two frontcourt players.

Cunningham is viewed as a close replacement for Arthur, and the Griz also have 76ers versatile big man Marresse Speights on their radar, according to sources with knowledge of the Grizzlies’ thinking.