"Sure," she said. "That sounds like fun."
And little did she know just how much fun it would be.
Magnuson went to the trials and won the 100-meter butterfly, an event in which she had ranked just 73rd in the world and 17th in the United States two years earlier.
Then she won a silver medal in the 100 fly at the Beijing Summer Games and a second silver medal swimming the butterfly leg on the U.S. medley relay.
"It never crossed my mind I would actually make the team," she recalled during a recent Chicago visit to give a clinic for young swimmers. "I wasn't just the underdog to everyone else. I was the underdog to myself."
The Olympic success drew sponsorships from Speedo, AT&T and Mutual of Omaha, allowing her the financial resources to continue swimming once she left the college scholarship cocoon. And, after a move in 2009 to Tucson, Ariz., Magnuson heads back to the Olympic trials that begin Monday in Omaha, Neb., in a familiar position.
After recording the world's fastest 100 fly time in 2010, Magnuson had a subpar 2011 season after losing training time to recurring illnesses that led to sinus surgery. She enters the trials as the sixth-fastest U.S. swimmer in the 100 fly this season, fourth in the 50 freestyle and 15th in the 100 freestyle.
Magnuson plans to swim those three events at the trials and needs a top-two finish in one of them to be guaranteed an Olympic spot. A top four in the 100 free could give her a place in the relay pool.
"It has taken me a while to get my confidence back," she said.
The 57.32 seconds she swam for 100 butterfly in 2010 provided some reassurance, since it came in the first season after swimming officials banned the "technological doping" provided by high-tech suits. Only one U.S. swimmer, Dana Vollmer, has swum faster (five times, with a best of 56.47) since the ban.
Although her races all are 100 meters or less, Magnuson has been working in Tucson primarily with one of the greatest distance swimmers in U.S. history, Rick DeMont, who set world records in the 400 and 1,500 freestyles.
"We call him the Rocket," Magnuson said.
She chose Arizona because there were a lot of post-grad swimmers her age training there. Magnuson left Tennessee with the Southeastern Conference's scholar-athlete of the year award, which provided a $15,000 scholarship she has used to complete the first year of a master's degree program in public administration.
"If I don't make the (Olympic team), I will probably retire, focus on finishing my master's and moving on to the next stage of real life," she said. "If I do, I will definitely swim another year to try for the 2013 World Championships.
"It's definitely harder (to make the team) again. The first time, I had no idea what to expect and no pressure. It helps make it a little easier that I am getting a master's so no matter what happens this summer, I have something to look forward to in the fall."
Talking about Beijing brings tears to Magnuson's eyes, an emotion spurred not by warm feelings over her OIympic success but by remembering the warm hearts that allowed her family to share the glory.
After the 2008 Olympics, a local TV station interviewed William and Geralyn Magnuson, both junior high school teachers, and asked if they were going to China. Geralyn said she wasn't sure if they could afford it.
Checks started pouring in from all over the Chicago area. Her parents and sister Jackie flew to Beijing.
"The generosity still chokes me up," Christine Magnuson said.
As she finished the 100 fly final, Magnuson was sure only that Australian star Libby Trickett had beaten her. Then she saw the "2" next to her name on the scoreboard and looked into the seats for her family.
Jackie was jumping up and down. Geralyn was crying. William was losing the fight to hold back tears.
"That," Christine Magnuson said, "was the most fun of all."