According to Jennifer Sullivan of the Seattle Times, police said Kendrick's home was robbed between March 30 and April 1.
Along with the ring, the thieves reportedly stole his framed Ken Griffey Jr. jersey, baseball gloves, bats, televisions and computers.
Lt. Chris Cammock said investigators aren't sure why the home alarm system failed to go off and are looking into whether burglars disabled the alarm.
Kendrick isn't the only Major League Baseball player who has been robbed recently.
Just before the season started, the spring training rental home of three Tampa Bay Rays players was burglarized.