Hawerchuk, who was selected by the Jets with the No. 1 pick in the 1981 NHL Draft and was their captain for six seasons from 1984-90, revealed earlier this week that he has stomach cancer and is receiving chemotherapy treatment.
The 56-year-old previously announced Sept. 3 that he was taking a leave of absence from Barrie of the Ontario Hockey League, where he has been coach since 2010-11.
During the luncheon, in an alumni discussion about heated rivalries of the past, former NHL defenseman Jamie Macoun recounted the series between the Flames and Jets in the 1985 Smythe Division semifinals. Macoun broke Hawerchuk's ribs with a cross check in Game 3, but the Jets would go on to win the best-of-5 series 3-1 before being swept by the Edmonton Oilers in four games in the division final.
That story prompted former Flames co-captain Lanny McDonald to ask all in attendance to keep Hawerchuk in their thoughts and prayers.
"He's in a fight for his life," said McDonald, who is chairman of the Hockey Hall of Fame. "I spoke to Dale two weeks ago and reminded him of being knocked down by Jamie. [I] encouraged him that, even though he's been knocked down many times in his life, this is one fight that he'll find a way to get back up and win all over again.
"In a spare moment, in your thoughts and prayers, make sure you say a couple for Dale Hawerchuk."
Hawerchuk had 1,409 points (518 goals, 891 assists) in 1,188 games, 20th in NHL history, with the Jets, Buffalo Sabres, St. Louis Blues and Philadelphia Flyers. He was inducted into the Hockey Hall of Fame in 2001.
"Dale Hawerchuk is royalty in the history of the Winnipeg Jets. He put that team on the map," Jets executive chairman Mark Chipman said. "And he's continued to be an incredible alumnus for us in so many respects. We're very, very proud to have him as part of our group. I'm praying for him and thinking about him every day.
"He seems to be doing OK. He's really appreciative for everybody that's been reaching out to him. He's in a battle and he knows it."