A “triple threat” man in football is a player who can run, pass and kick. Triple threat men were highly prized in the early days of football in the early 1900s, but the rise of specialists made them obsolete. “Moreover Bobby can hurl the pigskin and he will be a triple threat from this time on” was cited in print in October 1919. The term “triple threat” would be used frequently in the sports pages of he 1920s.
 
A show business “triple threat” is a performer who can act, sing and dance.
   
 
Wikipedia: Triple-threat man
In gridiron football, the phrase triple-threat man refers to a player who excels at all three of the skills of running, passing, and kicking. In modern usage, such a player would be referred to as a utility player.
 
Triple-threat men were the norm in the early days of football, as substitution rules were stringent. Thus, in addition to the need for passing, running, and kicking skills, they were also required to play defense. As injury awareness grew and substitution rules loosened, teams shifted to kicking specialists, which made the triple-threat man obsolete. One of the last triple-threat men in professional football was George Blanda, a quarterback and kicker who last played for the Oakland Raiders of the National Football League in 1975
 
(Oxford English Dictionary)
triple-threat adj.
1939   W. H. Baumer Sports as taught & played at West Point 40   Any backs who possess the three qualifications of being a good runner, passer and kicker to a marked degree are triple-threat men.
1972   J. Mosedale Football v. 67   Football no longer requires the triple threat back—the player who can run and kick as well as punt.
   
17 October 1919, The Sun (Baltimore, MD), “Like the Bobby of old”  by C. Starr Matthews, pg. 13, col. 1:
Moreover Bobby can hurl the pigskin and he will be a triple threat from this time on.
 
Chronicling America
11 November 1919, The Sun (New York, NY), “High Lights and Shadows in All Fields of Sport” by Daniel, pg. 17, col. 6:
Princeton dropped the kicking game as its main weapon and in its stead adopted an attack of versatility and great possibilities—an offense which put great stress on the threat as personified by Trimble, a kicker, a forward passer and a great runner. It was this triple threat with Eddie Mahan as the big figure, which demoralized Yale in 1915, and for a time on Saturday it surely shot Harvard to pieces.
   
Google News Archive
25 October 1920, The Sunday Tribune (Providence, RI), “Tiger machine too much for Annapolis,” second sec., pg. 5, col. 3
The series of plays that at resulted In the score all were of the triple threat style, that is, with a man in kick formation who can run, or pass.
 
Google Books
Football and How to Watch It
By Percy Duncan Haughton
Boston, MA: Marshall Jones Company
1922
Pg. 149:
Therefore, if the player in question is adept in kicking, running, and passing, whenever he assumes this ten yard position he constitutes a “triple threat”; and the defense must so arrange themselves as to be properly prepared for a kick, run or pass.
 
Google Books
Principles of Football
By John William Heisman
St. Louis, MO: Sports Publishing Bureau
1922
Pg. 233:
The rearmost man in the backfield, on a punt formation, should be what is known as a “triple-threat” man — he should be able to run the ends well, pass well and punt well, so the defense may not know what kind of a play is coming off merely because punt formation has been taken.
 
Chronicling America
16 November 1922, Evening Public Ledger (Philadelphia, PA), pg. 24, col. 1:
Language of Football Field Difficult for Many Followers of the Game to Understand
SHE LOVES FOOTBALL,
BUT WHAT’S THIS STUFF
ABOUT TRIPLE THREAT?
This Fannette Is Strong for Gridiron, but She Doesn’t
Understand the “Technical and Slangy” Way the
News and Comment Is Written
By STONEY McLINN
(...)
She adds: “What, pray tell, is the ‘triple threat’ you write so much about?”
(...)
Now, suppose the attacking team has a player who excels in all three departments—can run with the ball, kick and throw passes. Well, he is the “triple threat.”