"Too much basketball would overwhelm the electorate, would detract from his gravitas," Watterson said. "So I wouldn't expect him to be in too many pickup games, at least with the photographers around."
McCain, though much older than Obama and bearing disabilities from his time as a prisoner of war, could tout past physical exploits. But Watterson doesn't expect to see too much of that.
"You may hear a little bit about his wrestling in high school or other things," Watterson said. "If you're a fighter pilot you have to be a pretty good athlete, but I'm not sure that's what he's going to emphasize. ... Nobody's there to see it. And it also leads back, perhaps, to his days at the Naval Academy. And as I understand it, he was extremely rebellious, and that certainly wasn't part of his preparation for the presidency."
Paul F. Boller, author of "Presidential Diversions: Presidents at Play From George Washington to George W. Bush," and a professor emeritus of history at Texas Christian University, sees an increased emphasis on image over substance as a distressing trend in modern campaigns. He said, "Lord, if it's all personality, why don't each of [the candidates] take a screen test?"
Perhaps the trend gained momentum in the '80s when Ronald Reagan, a former actor, took the White House, and Democrat Michael Dukakis was undone in his White House bid partly by a much-ridiculed photo op of himself in a tank.
But even though the focus on prepackaged candidate photo ops may be a recent phenomenon, Boller and others say physical strength and athletics always have been part of presidential image-making.
"Theodore Roosevelt had his picture taken in all sorts of settings, but did not allow himself to be photographed playing tennis because he thought it was too effete," Waterman, the presidential image expert at the University of Kentucky, told ABCNews.com via e-mail. "Gerald Ford made much of his reputation as a college football player, as did George H.W. Bush and his stint at first base at Yale. Of course, George W. Bush was the owner of the Texas Rangers. He used that venue to promote his political rise in Texas to the governor's office."
When it came to the jock card, some presidents and candidates rode their physical skills to the hall of fame.
George Washington's reputation as a physically imposing, rugged general likely contributed to his leadership aura, Boller said.
The Kennedys were known for their raucous family touch football games, though in reality John F. Kennedy suffered from a bad back and other ailments.
Reagan was nicknamed "the Gipper," after a football player he portrayed in the movies, and was photographed looking rugged atop a horse.
Even Abraham Lincoln, not exactly remembered as a fine physical specimen today, successfully rode a similar macho-man vibe into office.
"His supporters portrayed him as the great rail splitter," Boller said. "He was good with the ax. He was strong enough to split wood and build fences. That was sort of the image his supporters tried to portray of him. So I'd say that was crucial because it showed he was one with the common man."
Less legendary presidents played the jock card, too.
Some say George H.W. Bush sought to toughen his reputation through athletics.