Suggs told ESPN's Rachel Nichols in a telephone interview that he injured himself practicing the conditioning test the Ravens make their players take. He was working out at his old high school in Chandler, Ariz. He said he started and stopped and felt something turn, so he called his trainer to get an exam.
In an earlier text to ESPN, he said the injury happened Saturday.
He said he is not on crutches, but confirmed he is having surgery next week. In earlier texts to ESPN, Suggs said he will meet with the surgical specialist Tuesday and that he expects to recover from the injury in four to six months.
Although the general length of time to full activity following the surgery is four to six months, the average return to playing in an NFL game is 11 months, according to a study presented at the American Academy of Orthopedic Surgeons in 2006.
Suggs, who turns 30 in October, said he has been stunned at reports that he will miss the season.
"That's just going to make it so much sweeter when I run out of that tunnel and prove everyone wrong," Suggs told Nichols.
He said the injury is the first major one in his career.
"I've never had a real bad injury before -- sometimes you have to go through something like this to make you better," he said.
In the earlier texts to ESPN, Suggs denied that the injury happened playing basketball, as some sources had told ESPN NFL Insider Adam Schefter. Other sources had told Schefter that the injury happened during the conditioning test, as Suggs maintains.
The Ravens, according to sources, have not yet seen results of Suggs' MRI.
Suggs was named the NFL Defensive Player of the Year after last season, in which he had 70 tackles, including 14 sacks, and was a threat all over the field from his hybrid linebacker-end position.
He also forced seven fumbles and had two interceptions, helping the Ravens, who boasted the No. 3 overall defense, win the AFC North and advance to the AFC Championship Game.
Suggs was the only player last season to record at least five sacks, five passes defensed and five forced fumbles.
Ravens general manager Ozzie Newsome told ESPN's Josina Anderson that the team found out about Suggs' injury earlier this week.
A statement released by the Ravens said: "We are in contact with Terrell. He will see a specialist early next week and we'll know more at that time."
In his nine-year career, Suggs had missed only three games. He is the Ravens' career sacks leader with 82½.
Replacing Suggs will be a challenge. The Ravens drafted former Alabama linebacker Courtney Upshaw, but he is expected to replace outside linebacker Jarret Johnson, who signed with the San Diego Chargers. Candidates to take over Suggs' spot are Paul Kruger, Sergio Kindle and Michael McAdoo.
Information from ESPN's Rachel Nichols, ESPN NFL Insider Adam Schefter, ESPN.com's Stephania Bell, ESPN.com AFC North blogger Jamison Hensley and The Associated Press was used in this report.