Cunningham, 26, remains in critical but stable condition and has not regained consciousness since collapsing before Tucson played Manitoba.
"The good news is he's progressed a lot from the state he was in last weekend," Lucic said. "He's heading in the right direction, but obviously there's a lot more progression and healing to be done. I can't go into [details] too much more than that.
"Being one of my best friends … to go there and show my support was something I wanted to do. I didn't want to overload him too much knowing that he needed to get some rest. I just wanted to do my part and show my support to him and his family. I think it was important to kind of take their minds off of what's going on … talk about me, my family, and bring a positive vibe."
Lucic first met Cunningham when they played together for Vancouver of the Western Hockey League, Lucic in his final season of juniors and Cunningham as a shy 15-year-old whose father had died in a car accident.
"He's been through a lot of hardship in his life, but he's always battled through it," Lucic said. "Even then, he had the determination and drive that let you know he was going to do everything he could to reach the NHL."
Cunningham did just that in the 2013-14 season, when he played his first two NHL games. As fate would have it, Lucic again was his teammate with the Boston Bruins, and the following season, they played on the same line for a few games in December, including when Cunningham scored his first NHL goal Dec. 13, 2014, against the Ottawa Senators.
"Being down here with a day off, I would have been kicking myself if I didn't go down to see him," Lucic said. "Driving back, I definitely felt better about the situation and hopeful of him making a full recovery. I'm just hoping he can be strong and pull through.
"Every guy who ever played with him will give you the same feedback; they will talk about how good a teammate Craig Cunningham is."
Cunningham, who is Tucson captain, played 10 games for the Coyotes last season and has three goals and five assists in 63 NHL games for Boston and Arizona.