Starting pitcher Hisashi Iwakuma #18 of the Seattle Mariners pitches in the third inning against the Kansas City Royals at Safeco Field on September 25, 2013 in Seattle, Washington. (Photo by Otto Greule Jr/Getty Images)

by Curtis Crabtree
KJR reporter
Twitter: @Curtis_Crabtree

Pitchers and catchers are reporting to Peoria, Ariz. for the start of spring training and the Seattle Mariners already have an injury to a key member of their starting rotation.

The team announced Wednesday that Hisashi Iwakuma suffered an injury to the middle finger on his throwing hand while working out in California.

Iwakuma was examined by hand specialist Dr. Don Sheridan in Arizona and was diagnosed with a strained tendon in his middle finger. Iwakuma's finger has been placed in a splint and he will not throw for four-to-six weeks. Surgery is not expected to be necessary.

“Luckily, this does not appear to be a serious injury,” general manager Jack Zduriencik said. “It is a setback for Kuma, but we are confident that he will quickly overcome the missed time and be able to rejoin our rotation early in the regular season.”

If there aren't any setbacks, Iwakuma shouldn't miss too much time for the start of the season. However, it now leaves a hole in the rotation that will need to be filled at least temporarily.

Iwakuma is expected to be the No. 2 starter for Seattle behind Felix Hernandez. Assuming Iwakuma isn't ready for opening day, the Mariners will need to have a contingency in place of carrying an extra starter on their roster or having a long reliever capable of a couple spot starts ready to go.

While the injury certainly won't have a major impact on Iwakuma's season, it's still not the way a team would like to start spring training.

Iwakuma posted a 14-6 record last season. He threw 219.2 innings with a 2.66 ERA in 33 starts.