It's not that the Seattle Mariners didn't expect Ken Griffey Jr. to be elected into the Hall of Fame; they were just waiting for it to officially happen.

The Mariners now plan to retire Griffey's No. 24 during the 2016 MLB season. The former MVP received the highest vote percentage (99.3 percent) of any Hall of Famer in MLB history after becoming a first-balloter last week.

"Ken Griffey Jr. was the first player selected in the 1987 Draft, a first-ballot Hall of Famer, the first player in Hall of Fame history to amass over 99 percent of the vote and the first player to wear a Mariners cap on his Hall of Fame plaque," Mariners president and CEO Kevin Mather said in a team press release. "It seems only fitting that he be the first Mariners player to have his number retired."

Griffey's number will be retired during a pregame ceremony on Aug. 6 before the Mariners host the Los Angeles Angels at 6:10 p.m. ET during Ken Griffey Jr. Weekend at Safeco Field: Aug. 5 will be Ken Griffey Jr. Hall of Fame Bobblehead Night and Aug. 7 will be Ken Griffey Jr. Replica Jersey Day.

It will be the first time in the team's 39-year history that a Mariners' player will have his number retired. The only other retired number for Seattle is Jackie Robinson's No. 42, which is retired throughout the MLB. Griffey sounded honored to have his number hang alongside Robinson's at Safeco Field in the near future.

"Having my number next to him, I don't think I did half of what he did," Griffey said, via The Associated Press. "Baseball-wise, yeah, you're going to look at numbers and things like that, but the way he went about his life and the things he did off the field, nobody can compare to that. He is a trailblazer in more ways than one."

Coincidentally, it was Griffey who asked former MLB commissioner Bud Selig if he could wear No. 42 on Jackie Robinson Day, which is now an annual tradition for every player and coach.

Griffey also became the first Mariner elected into the Hall of Fame. His former teammate, Edgar Martinez, has been on the ballot for seven years and received 43.3% of the vote this time around, but it was Griffey's record-setting 99.3 percent that is the talk of the MLB.

"It means a lot," Griffey told Greg Johns of MLB.com. "Anytime somebody does something for you, you can't take it for granted. The writers voting, the Mariners not telling me until the last moment they were going to do this, it means a lot."