The 29-year-old was in Florida on Sunday when a teenage girl saw and ran at the 6'2" athlete, USA Today reports.
Lochte – who starred in his own reality show, What Would Ryan Lochte Do?, earlier this year – caught the girl but they toppled over. While the teen was unharmed, he hit the curb, blowing out his left knee.
"As a result of a freak injury caused by an unexpected fan encounter, Ryan has suffered a torn MCL and an ACL sprain and will be taking a break from training and competition," his publicist said in a statement.
"His medical team expects him to make a full and speedy recovery and Ryan thanks everyone for their well wishes."