It was thought the match could return to the rebuilt Wembley, but will be staged in Cardiff for the seventh season - on Sunday April 1.
"It is a real coup for us to have persuaded the Football League to come back for another showpiece occasion," said stadium manager Gerry Toms.
The competition involves all League One and League Two clubs, and was won last season by Swansea City.
Five League One clubs remain in the competition, which is currently at the regional semi-final stage.
Doncaster, Chesterfield and Crewe are in the northern section, with Bristol City and Brighton left in the southern section.
Scunthorpe's involvement in the competition lasted just two rounds - but was eventful.
They were fined by the Football League after fielding an under-strength squad in the 2-1 first round win over Bradford in Octobber.
Under rules introduced this summer, each team participating was forced to select at least eight of their most regularly used players.
And the Iron exited the competition a fortnight later when a goaless draw with Port Vale at Glanford Park was followed bya 5-3 penalty shootout loss.