Ken Griffey Jr. became a huge star in Seattle, then beelined back home to play in Cincinnati.

Now that he's capped off his career with a trip to Cooperstown, a juicy question: Will Junior wear a Mariners or Reds hat on his Hall of Fame plaque?

Or maybe there's a third option, as reigning NL MVP Bryce Harper tweeted Wednesday.

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''Juniors ball cap has to be backwards on his plaque right?'' the Washington Nationals slugger posted.

That's how Griffey often flipped his lid, having fun while getting ready for games.

''I haven't really thought about the hat backwards,'' Griffey later said on a conference call.

As to his preference, he added: ''I'll think more about it tomorrow.''

Mike Piazza could make a case for two logos, too. He was the Rookie of the Year and the All-Star Game MVP with the Los Angeles Dodgers, later making his only World Series appearance with the New York Mets.

''I'm under strict orders to keep it confidential until tomorrow,'' Piazza said.

The Hall of Fame actually makes the final call on caps. New inductees can express their wishes and talk it over with the Hall staff, but they don't get the last say.

Not every Hall player has a logo, either.

Greg Maddux excelled with the Cubs and Braves and felt strongly about both places, and the hat on his plaque is blank. Same with Tony La Russa, who managed both the Athletics and Cardinals to World Series championships.

There also was speculation about Randy Johnson (Diamondbacks over Mariners), Gary Carter (Expos over Mets) and Andre Dawson (Expos over Cubs) before their bronze plaque logos were picked.

Griffey's best years came in Seattle. The slugging center fielder was an All-Star and Gold Glove winner for 10 straight seasons with the Mariners, and rejoined them to close his career.

Griffey played nine seasons with the Reds, often slowed by injuries. He hit 417 homers for Seattle and 210 for Cincinnati.

Piazza set the career record for home runs by a catcher while playing for the Mets. That included a most memorable drive in the first major New York City sporting event following the 9-11 terrorist attacks.

Piazza earned a $91 million contract with the Mets, was back in town when they reached the World Series last year and has been a spring training instructor for them.

Much earlier, Piazza emerged as a perennial All-Star with the Dodgers and played parts of seven seasons in L.A. before acrimonious circumstances as he neared free agency led to a trade.

''My time with the Dodgers was very interesting,'' he said.