Imagination is about all sports fans have going for them at the moment, and NFL fans were given a real doozy of a challenge in that realm Tuesday: Suddenly, we are forced to picture Tom Brady in a uniform other than that of the New England Patriots.

Among active stars in baseball, there is no real equivalent that would provide such a jolting effect on the fan base. Brady might rate as the best NFL player of all time, and every ounce of value he has produced as a professional has come with the Patriots over a period that covers the entirety of the century. Brady was drafted by New England a couple of weeks after the 2000 MLB season began. There are no active big leaguers who played that season.

As someone whose all-time favorite baseball player is George Brett, perhaps I place more importance on the concept of the one-team Hall of Famer than I should. Yet I'm not the only one. There is even a Wikipedia page listing every player who lasted at least 10 years in the majors and spent them all with one franchise. The Hall of Famers receive special notation on that page, as they should. It's a precious thing, the one-team Hall of Famer. Brett is on that list, and though he retired more than a quarter century ago, he very much remains the most iconic personality in the history of the Kansas City Royals. And Royals fans don't have to share him with anyone.

You can say the same thing about Cal Ripken (and Brooks Robinson and Jim Palmer) with the Orioles. Robin Yount with the Brewers. Derek Jeter (and Lou Gehrig and Joe DiMaggio and Mickey Mantle) with the Yankees. Ted Williams (and Carl Yastrzemski) with the Red Sox. Johnny Bench with the Reds. Stan Musial with the Cardinals. There is something very special about the dynamic: the one-team Hall of Famer. After Tuesday's shocking tweet, Brady will no longer be that for Patriots fans.

At the same time, we're talking about professional sports. That Brady will play for somebody else -- and it looks like it will be the Bucs -- doesn't mean that he'll ultimately be remembered as anything but the Patriots' quarterback. All through the ages, even the greatest players have changed teams, often at the very end of their career, when they just wanted to keep playing. Michael Jordan played for the Washington Wizards. Willie Mays played for the Mets. Hank Aaron played for the Brewers. Ty Cobb played for the Athletics. The one-team Hall of Famer is such a special thing because it happens so rarely.

While acknowledging that there currently is no MLB player who could change teams tomorrow and create quite the same stir as Brady, that doesn't mean there aren't a few stars building up to becoming something similar. In fact, baseball has a few candidates to eventually join that exclusive list of one-team Hall of Famers. Most of them already have reached the point that to see them in a new uniform would be jarring, to say the least. But if it can happen with Brady, it can happen with anyone.

Here are a few one-team Hall of Fame candidates whom we hope to see back on the field in their familiar threads sooner than later, and a few others who are probably not Hall of Famers but nonetheless are synonymous with the teams for which they've always toiled. To illustrate the effect I'm referring to, I conclude the list with a few players who will fall off as soon as regular-season baseball resumes. If we had done this list a year ago, it would have been weird to imagine them in new uniforms. But this spring, those imaginings have turned into strange new realities.