When Josh Onomah and Kyle Walker-Peters joined up with the England Under-20 squad in May, there was a school of thought that they would have been better off staying at Tottenham.

Spurs' final two matches looked like an ideal moment to give the youngsters some game time, and there was some disappointment that Walker-Peters was not around to make his first-team debut.

Yet the U20 World Cup has proved to be a wonderful and invaluable experience for both players, who will return to north London after winning a major international youth tournament.

Many supporters will have caught their first glimpses of Walker-Peters in South Korea, and the 20-year-old full-back impressed, showing a cool-headed confidence on the ball and a useful burst of pace. Despite being right-footed, he played at left-back, showing his versatility.

Meanwhile, Onomah will have changed a number of fans' opinions. He endured a largely disappointing 2016-17 season at White Hart Lane, struggling to get game time, failing to consistently make an impact and watching as his fellow academy graduate Harry Winks became a first-team regular.

Yet Onomah has been hamstrung by the fact that Mauricio Pochettino has mostly used him on the right side of the front four, whereas he really prefers a more central, deeper-lying role.

At the World Cup he was able to show his true potential in his best position, and he excelled with and without the ball, making good use of his superior strength relative to his peers to win the ball back repeatedly and make driving runs forward. He was unlucky not to score in the final after lashing a 25-yard rocket against the crossbar.

Suddenly, Onomah is earning comparisons with Mousa Dembele -- quite a change from the way most Spurs supporters probably viewed him before the tournament -- and it is now clear why Pochettino has kept him with his first-team squad rather than sending him out on loan.

Of course, it is easy to overhype young players and some caution is required. Last August there was great excitement about 18-year-old Marcus Edwards, but he only ended up playing 15 minutes during the course of the campaign.

Walker-Peters and Onomah have certainly underlined their potential, but they will soon return to the reality of trying to make an impact at a title-chasing Premier League club, where their rivals and opponents are senior internationals rather than U20 talents.

It remains to be seen how Pochettino will use the pair next season, and there is plenty of time for them to develop under their manager's expert eye. Winks had to wait for his big break.

Yet at the same time, forward planning dictates that certain decisions must be made now, because the anticipated timing of any advancement for either player will directly influence how Spurs approach this window.

After all, it would be counter-productive if a new signing blocked the path of an up-and-coming academy player who could capably fill the spot without the need for a transfer fee.

Pochettino was mindful of that last summer when he decided not to replace Federico Fazio, choosing instead to leave room in his squad for teenage centre-back Cameron Carter-Vickers.

That approach once again underlined his commitment to youth development, but it is also risky. Carter-Vickers struggled in two of his four appearances last term -- against Liverpool in the EFL Cup and Wycombe Wanderers in the FA Cup -- and was benched from February onwards.

Now Kyle Walker's future is uncertain, while on the other flank Spurs have been linked with Fulham's 17-year-old left-back Ryan Sessegnon.

Kyle Walker-Peters helped England win the Under-20 World Cup in South Korea. Maddie Meyer - FIFA/FIFA via Getty Images

Walker-Peters' readiness to play as a right-back, a left-back or both is therefore a pressing issue.

Given he is yet to make his debut, it seems rather optimistic to anticipate that he could hold his own in the Premier League next season. But could he be at that level in the next couple of years?

If that is the hope then it will surely influence Spurs' plans for the coming weeks -- how many full-backs they might sign, and how old those players might be, given they seemingly already have one for the future.

Similarly, Tottenham need to plan for life after Dembele at some stage. While Onomah has a long way to go to emulate the Belgian's ability and may never reach that level, he has strengthened his claim for a central midfield berth in the long term. With Winks also progressing quickly, is another signing required in that position?

Pochettino again faces a tricky balancing act as he attempts to improve his squad and win silverware next season while also giving the club's best academy products room to grow, in accordance with his and Tottenham's ethos.

The good news is that Spurs have the ideal man for these issues, and he will undoubtedly be pleased to have these dilemmas; to see two more youngsters showing encouraging signs of being future first-team regulars.