While the Leicester City hitman was firmly a back-up to Harry Kane with the national side, he was arguably England’s most natural finisher, and will need replacing.
Three of Southgate’s options—Dominic Solanke, Tammy Abraham and Ademola Lookman—are players who are still, at the time of writing, eligible to feature for Nigeria, and should the coach look to fast-track one of the three, Vardy’s decision could have consequences for the Super Eagles.
The immediate future for the trio may depend on how Southgate opts to replace Vardy.
Surely, Marcus Rashford—who was arguably ahead of the 31-year-old in the pecking order anyway—will get more of an opportunity to shine, while Vardy’s exit could mean a return to prominence for Danny Sturridge, Danny Welbeck or Theo Walcott.
Similarly, Southgate might opt to consider Bournemouth’s Callum Wilson, who has two goals and one assist in the top flight so far this season.
Perhaps more likely, however, is that the former England defender will plump for youth, and turn to one of the players he worked with in the Three Lions’ youth set-up.
Dominic Calvert-Lewin, Jadon Sancho and Ryan Sessegnon are all at early stages of their development, but an opening in the squad could see Southgate look to give one of the trio a more prominent role.
Solanke and Abraham also fit into a similar category.
Having only played in friendly fixtures to date, they’re still eligible for Nigeria, but that may soon change if Southgate sees them as potential Vardy replacements.
Both are talented players, even if their recent form suggests they’re not yet truly ready for life in the England squad.
He’s reportedly refused to move away on loan, but if he stays at Stamford Bridge, it’s hard to see quite how he’ll get enough opportunity to impress Southgate.
Nonetheless, his credentials make him a fascinating prospect, and if Southgate has faith, he could move to give the wonderkid an earlier-than-planned opportunity to reaffirm his quality in national team colours.
If England don't reconsider this out-of-sorts talent, then Amaju Pinnick and Gernot Rohr surely should...
Southgate is understood to be an admirer of the attacker, who offers something a little different to his current options, and Vardy’s abdication could represent an opening if Solanke can find his feet at Liverpool.
Jurgen Klopp hasn’t invested in a new striker this season, and with Sturridge infamously injury-prone, we’ll likely get the chance to see whether Solanke can make a strong enough case to replace Vardy.
The most enticing of the three, if perhaps the least likely, is Everton wonderkid Lookman.
His immediate future at Goodison Park appears uncertain, even though Marco Silva’s described him as the future of the club, and a return to RasenBallsport Leipzig isn’t completely off the cards.
His form in the Bundesliga last term—five goals, three assists in 11 outings following a January move—indicates that he knows where the goal is, even if he’s nominally more of a wide player than Vardy.
For now, Nigeria fans can still hope that this exquisite talent will one day opt to throw his hat in the ring for the Super Eagles.
However, Vardy’s retirement leaves Southgate with a goalscoring spot to fill in his squad, and the precocious Lookman could be the man to fill it.