January is traditionally a time of frugality for most people after a costly Christmas period, but not football club owners. While the rest of us are trying to scale back on expenses and watching what we eat and drink after weeks of indulgence, managers, chairmen and sporting directors are braced for a hectic month of activity as they look to bolster their teams for the final few months of the season.
While the winter transfer window is never as busy as it is in the summer, plenty of money is still thrown around, with Chelsea breaking the world transfer record last season to sign Enzo Fernandez, as well as pinching Mykhailo Mudryk from under Arsenal's noses.
And some of the most shrewd transfers in Premier League history have been made in January, as this list of transformative signings demonstrates...