Jim Thorpe's athletic profile is the stuff of legend. After playing for Pop Warner's famous Carlisle Indian School team and being the 1912 Olympic decathlon champion, Thorpe went on to play baseball for the New York Giants in addition to being one of the instrumental figures in the organization of the NFL in 1920. (Associated Press)
» Thorpe: 1963 Hall of Fame inductee

Sammy Baugh getting stuck behind eventual National League MVP Marty Marion in the St. Louis Cardinals' minor league system turned out to be a boon for the Washington Redskins, who won two NFL championships with "Slingin' Sammy" as their quarterback. (Associated Press)
» Baugh: 1963 Hall of Fame inductee
» Remembering Sammy Baugh | The most versatile player in NFL history

The NFL career of Clarence "Ace" Parker sounds like something you'd find in the Baseball Encyclopedia. Parker played for the Brooklyn Dodgers, Boston Yanks and New York Yankees ... of the NFL. Parker became the first two-sport athlete when he played for the Philadelphia Athletics of Major League Baseball and the Brooklyn Dodgers (of the NFL) simultaneously in 1937 and 1938. (AP Photo/BFG)
» Parker: 1972 Hall of Fame inductee

When the Baltimore Colts made John Elway the top player chosen in the 1983 NFL Draft, the former Stanford QB/right fielder threatened to turn to baseball -- he had played two summers in the minors for the New York Yankees. Instead, the Colts traded Elway to the Denver Broncos, a team Elway led to five Super Bowls, winning two. (AP Photo/Paul Sakuma)
» Elway: 2004 Hall of Fame inductee
» Elway: Career retrospective | In the Super Bowls | Top 10 moments

"Bo knows" became a popular phrase in sports in the late 1980s, when Bo Jackson became an all-star outfielder for the Kansas City Royals and a big-play running back for the Los Angeles Raiders. (AP Photo/Lenny Ignelzi)
» Top 10 draft steals: Bo Jackson

While toiling in the St. Louis Cardinals' minor-league system, Brian Jordan played defensive back for the Atlanta Falcons -- playing alongside another baseball/football player, Deion Sanders. Jordan eventually switched to baseball full time, enjoying a productive career with the Cardinals, Atlanta Braves, Los Angeles Dodgers and Texas Rangers. (AP Photo/John Bazemore)

Deion Sanders became the first athlete to play in both the World Series and Super Bowl. Sanders played in one World Series -- in 1992 with the Atlanta Braves -- and in two Super Bowls -- in Super Bowl XXIX with the San Francisco 49ers and Super Bowl XXX with the Dallas Cowboys. (Associated Press)
» Highlights of the decorated career of "Prime Time"
» Sanders: One true character | A real return ace | A top cornerback tandem

New York Mets outfielder and Minnesota Vikings running back D.J. Dozier checks out his lumber in front of his locker at the Mets spring training camp at Port St. Lucie, Fla., Feb. 18, 1991. Dozier is at the Mets camp as a promising minor leaguer who is trying to play both football and baseball. (AP Photo/Richard Drew)

Dallas Cowboys owner Jerry Jones, right, speaks to the media with St. Louis Cardinals pitcher and former Stanford quarterback Chad Hutchinson after a news conference in Irving, Texas, Saturday, Jan. 26, 2002, where it was announced that Hutchinson signed a contract with the Cowboys. (AP Photo/LM Otero)

Dallas Cowboys quarterback Drew Henson throws during the first quarter against the Chicago Bears in Irving, Texas, Thursday, Nov. 25, 2004. Henson picked baseball over the NFL coming out of college and spent time with the New York Yankees and the Cincinnati Reds organizations as a third baseman. (AP Photo/Tony Gutierrez)