When football impacts on language...
The English Dictionary, Montgomery-Smythe Publishing Associates 2017 Edition:
1. To ‘do a Leicester’. To enter a competition or contest as an underdog thought to have little or no chance of winning, and yet achieve unexpected or astonishing success.
Example: ‘I hope we can do a Leicester next season.’ Antonym: To ‘do a Chelsea’.
2. To make an impossible dream come true.
. . . . . . . .
Here are a few examples…
“Former Huddersfield Town man out to ‘do a Leicester’.”
“James McCarthy urges Scotland to ‘do a Leicester’.”