Gutierrez was injured Tuesday while making a throw from the outfield during a drill. He flew to Seattle on Wednesday and, after an MRI and a meeting with team doctors, the diagnosis was confirmed. Gutierrez will be held out of all baseball activities for at least a month and be re-evaluated at the end of March. He will miss all the spring training games and the Mariners' season-opening series against Oakland in Japan.
Earlier on Wednesday, Seattle manager Eric Wedge said there was "considerable concern" about Gutierrez's injury. Gutierrez was examined in Seattle by Dr. Edward Khalfayan. Wedge said it appeared to be an uncommon injury.
The Mariners said Gutierrez will be treated non-surgically in the hopes he can return this season.
Gutierrez was being counted on to bounce back from a disappointing 2011 season, when he battled stomach problems that caused him to play most of the season underweight. He gained nearly 20 pounds in the offseason and his health was one of the big stories in the early days of spring training.
Gutierrez was limited to 92 games last season and hit .224 with one home run. In his first season with Seattle in 2009, Gutierrez batted .283 and had 18 homers.