Gudbranson spent all five of his NHL seasons with the Panthers and signed a deal for the 2016-17 season this month. He had 11 goals and 32 assists in 309 games with Florida, helping the team reach the playoffs twice after being the No. 3 overall selection in the 2010 draft.
McCann just turned 20 earlier this month. He had nine goals and nine assists for Vancouver this season. The Canucks got him with the No. 24 overall pick in the 2014 draft.
The Panthers also got a second-round and fourth-round selection in this year's draft, and sent a fifth-rounder to the Canucks.