London - If Tottenham Hotspur's comprehensive defeat of Everton confirmed their standing as genuine contenders in the Premier League title race, it also underlined the value of Son Heung-min to Mauricio Pochettino's side.
The South Korea international was outstanding in the 6-2 victory at Goodison Park and will again be expected to exert his influence when Spurs attempt to apply further pressure on Liverpool and Manchester City when they face Bournemouth at Wembley on Wednesday.
Yet while Son's emergence as one of the Premier League's most effective forwards this season has strengthened the belief that Pochettino's side can push the top two all the way, his form also highlights the potential impact of his absence when he departs for the AFC Asian Cup in January.
Spurs have already moved to limit the effect of the tournament by negotiating with the Korea Football Association that Son should be allowed to join up with international team-mates in the United Arab Emirates following the London club's meeting with Manchester United on January 13, three weeks after foreign-based players would be expected to join the national squad.
His absence, though, will still be felt with Son set to miss league meetings with Fulham, Watford and Newcastle United, if South Korea advance to the final, as well as the League Cup semi-final second leg against capital rivals Chelsea and a potential FA Cup fifth-round tie.
At a crucial stage of the season, the loss of any senior player would be felt.
When that player has been performing as consistently as Son, the loss could affect Spurs' chances of ending their wait for silverware under Pochettino.
The manager has a number of other match-winners he can turn to with Erik Lamela and Lucas Moura having shown already this season they are capable of turning games.
And as good as Son has been in recent weeks, Harry Kane remains Tottenham's talisman.
But the South Korean has progressed to the extent that there is no doubt his loss will be keenly felt.
Against Everton, he scored twice but his contribution to England forward Kane's second goal demonstrated why Son is now an integral member of Pochettino's side. Drifting wide to collect a ball on the left, his first-time cross teed Kane up perfectly.
His goals at Goodison Park took his tally to five in his last six games, with Son's fine goal against Leicester demonstrating he has the knack of providing a decisive intervention when Tottenham fail to click in their usual manner.
At least Pochettino can be relieved Son is available for the gruelling Christmas and New Year programme.
The Everton fixture marked the first in a tough schedule that will see Spurs play five games in 13 days and the manager will draw on his squad depth to limit the effects of fatigue.
An international tournament will add to the demands on Son, but if he is able to maintain the form and fitness he has showed during the first half of the season when he returns from the Asian Cup, Tottenham's prospects of success will only be strengthened.