The Minneapolis Star Tribune reports, "Lucia said he broke his left fibula and suffered ligament damage in his left ankle when a teammate fell on him during a battle drill" on Wednesday.
Lucia was chosen in the second round (No. 60) of the 2011 NHL Draft. He is ranked as the Wild's No. 10 prospect by NHL.com.
"Hopefully I'll get back quicker than three months, but I'm in a cast for seven weeks, so there's not much I can do about that," Lucia told the newspaper's website.
Lucia is considered a candidate for the United States team that will play at the World Junior Championships. He had a hat trick in a split-squad game against Finland at the Evaluation Camp in Lake Placid, N.Y., earlier this month.
"Hopefully I can get a few games in before the world junior camp," Lucia said. "In the meantime, I'll just work to do well in school and have a good second half. But this is very disappointing."