A grueling summer of soccer for Son Heung-min took in the World Cup in Russia, a preseason tour to the United States, then the Asian Games in Indonesia where he played six games in 18 days in stifling conditions.

The South Korea superstar returned to Tottenham on Wednesday with a gold medal, an exemption from military service in his home country, and likely some tired legs.

Yet, the hard work doesn't end there.

Son is faced with the tough task of battling back into the Tottenham team, with fellow winger Lucas Moura having excelled in his teammate's absence during the last three matches in the English Premier League.

Moura's three goals — two of which came against Manchester United at Old Trafford — helped him win the Premier League player of the month award for August, and handed Tottenham manager Mauricio Pochettino something of a dilemma now Son is back.

Does Moura's form give Pochettino the option of even giving Son a well-earned rest? After all, the winger has barely stopped since linking up with South Korea in late May for warm-up games ahead of the World Cup finals. As if he hadn't played enough this summer, Son played almost every minute of the national team's friendly games against Costa Rica and Chile over the past few days.

It seems the 26-year-old Son doesn't want that, though.

"Fatigue is an excuse," Son said after the 0-0 draw with Chile on Tuesday.

Tottenham's hectic upcoming schedule may require Pochettino to throw Son straight into action.

A home game against Liverpool on Saturday starts a run of seven fixtures in 22 days across three competitions for the London club. That includes the start of the Champions League and it's hardly a slow introduction to the group stage: Spurs play Inter Milan and Barcelona in their first two matches.

There's a chance Son will not start against Liverpool at Wembley Stadium — although the absence of Dele Alli because of a hamstring injury does leave an available spot in the forward line — but will return for the trip to Inter three days later.

Moura will not be easy to oust. The Brazilian has more goals than Harry Kane this season, often finding himself further forward than the England striker as he cuts in from the right wing. It seems to be a similar tactic to Liverpool, where right winger Mohamed Salah often plays in advance of central striker Roberto Firmino, who can drop deeper like Kane.

Son is coming off his best season for Tottenham, scoring 18 times in all competitions and proving as adept at filling in as a striker in the absence of Kane as playing in his usual position on the left wing.

With Erik Lamela also providing competition in attack and both Alli and Christian Eriksen seemingly mainstays in Pochettino's team, Pochettino has never had such a wealth of options up front.

Tottenham started the Premier League with three straight wins before losing at Watford 2-1 before the break for international matches.

MORATA'S MISSION

Alvaro Morata might be running out of opportunities to convince Maurizio Sarri that he should be the first-choice striker at Chelsea.

Morata has one goal in his first five games of the season — after a preseason when he failed to score at all — and looked off the pace in Chelsea's most recent games, against Newcastle and Bournemouth.

Olivier Giroud, who scored a spectacular volley for France in the international break, has impressed as a substitute for Chelsea and might have convinced Sarri he is worthy of a start against Cardiff on Saturday.

Alternatively, Sarri could repeat what he did to such good effect at former club Napoli last season and play three smaller, more energetic forwards in the front line in Eden Hazard, Pedro Rodriguez, and Willian. At Napoli, Sarri used Jose Callejon, Dries Mertens, and Lorenzo Insigne.

Either way, Morata's spot looks up for grabs as he struggles to prove worthy of the club-record fee of 58 million pounds (now $80 million) that Chelsea spent to sign him from Real Madrid in the offseason of 2017.