SEATTLE -- There’s no question that the No. 51 will eventually be retired by the Mariners, almost certainly as the next jersey to be hung on T-Mobile Park’s center-field façade next to Ken Griffey Jr.’s No. 24 and Edgar Martinez’s No. 11.

The only question, it seems, is how soon 51 finds its way to the wall and whether it will first be raised for Randy Johnson, Ichiro Suzuki, or both at the same time.

• Mariners all-time retired numbers

Like all Major League teams, the Mariners have high standards for choosing when to retire a number. No number can be retired until the player who wore it has been voted on once for the National Baseball Hall of Fame, which essentially means six years after retirement from MLB. Additionally, that player must have “come close” to being elected into Cooperstown and have spent at least a “substantial portion of his career” with the Mariners.

Griffey and Martinez are the only Mariners to meet those standards to date. But Ichiro certainly checks those boxes and will undoubtedly be a first-ballot Hall of Famer and go into Cooperstown wearing a Mariners cap when he becomes eligible in 2025.

Having spent 14 of his 19 Major League seasons with Seattle and earned all 10 of his All-Star and Gold Glove Award selections as well as his AL MVP and Rookie of the Year Awards with the Mariners, Ichiro is a slam dunk to have his No. 51 retired by the club that still employs him as a special assistant to the chairman and outfield coach.

But how does the "Big Unit" fit into the equation, given he wore the same digits before Ichiro?

Johnson already has been elected into the National Baseball Hall of Fame, as a first-ballot selection in 2015. He also is one of nine members of the Mariners Hall of Fame, having been inducted in '12, two years after he retired.

The lanky lefty had his greatest success with the D-backs. He won four of his five Cy Young Awards and a World Series MVP Award and championship during his eight seasons in Arizona. Plus, he’s wearing a D-backs hat on his Hall of Fame plaque in Cooperstown.

But Johnson played 10 seasons in Seattle and won more games (a 130-74 record) with the Mariners than he did with the D-backs (118-62). He also won his first Cy Young Award while with the Mariners, made five of his 10 career All-Star teams and threw a no-hitter in a Seattle uniform.

So a strong case can certainly be made that Johnson deserves to have his No. 51 retired in Seattle, just as it has already been with the D-backs, and it’s possible the Mariners could do that without waiting for Ichiro’s time to come in five years if Johnson is amenable.

Three MLB teams have retired two players with the same number. The Yankees retired No. 8 for catchers Yogi Berra and Bill Dickey on the same date in 1972. The Cubs retired No. 31 for standout pitchers Ferguson Jenkins and Greg Maddux at the same time in 2009.

But the Nationals/Expos retired outfielder Rusty Staub’s No. 10 in 1993, then retired Andre Dawson’s No. 10 four years later. Dawson was playing for the Red Sox in '93, so the Expos couldn’t retire his number until his 21-year career ended in ’96.

So there is precedent for a team to retire two players with the same number, as well as doing so in separate ceremonies and seasons if needed.

Ichiro has always expressed gratitude to Johnson for allowing him to wear No. 51 during his Mariners tenure, which began three years after Johnson was traded to the Astros in 1998.

"Randy is a great pitcher, and he was a Mariner, and he wore No. 51 before me,” Ichiro said during his rookie season in 2001. “One of the things I always keep in my mind is to keep this number with dignity. I play with the Mariners with No. 51 with dignity because I inherited good things from Randy with the number 51."

Ichiro got an infield single off Johnson in the 2001 All-Star Game and hit .444 (8-for-18) with a double off him during regular-season meetings over the course of their careers.

So while the two have never played on the same team, they have shared a number and amazing success over lengthy MLB tenures. Now the question is whether they’ll someday share a retired number in Seattle, or perhaps even a number retirement ceremony in five years.