Petruzalek, 21, is in his first professional season, tallying two assists in six games for Hartford of the American Hockey League, and one goal and nine assists in seven games with Charlotte of the ECHL. The Rangers selected Petruzalek in the ninth round of the 2004 draft.
Isbister, who signed with Carolina as a free agent in August, has three goals and five assists in nine games with Albany of the AHL.