What can we expect from Neymar at Qatar World Cup?

Brazil kick off their quest for a record-extending sixth World Cup title when they play Serbia in Lusail, Qatar on Thursday with all eyes on Neymar who could be playing in his last finals.

Here is a look at the 30-year-old's World Cup highs and lows:

Missing out in 2010

Neymar burst onto the international stage in 2010 with a goal on his debut against the United States, but his career has been a rollercoaster where he has struggled to live up to high expectations and endured frustration with Brazil.

The striker was left out of the national squad for the 2010 World Cup in South Africa by coach Dunga, who did not believe the then 18-year-old was ready for the greatest stage despite making a name for himself in the Santos first team.

More heartbreak in Rio

Having become a household name after his move to Barcelona, a lot was expected from Neymar who spearheaded Brazil's attack at the 2014 World Cup on home soil, but the event would end in tears for the talismanic player.

Neymar -- who scored four goals in five matches -- sustained a cracked vertebrae in Brazil's quarter-final win over Colombia and was forced to watch his team mates suffer a humiliating 7-1 semi-final thrashing by Germany.

Injuries and tattered reputation 

Injuries would deny Neymar again at the global showpiece in Russia in 2018 -- only two years after he delivered Brazil's first men's Olympic gold in soccer with the winning penalty in a 5-4 shootout triumph over Germany at Rio de Janeiro.

Neymar suffered a sprained right ankle that affected the fifth metatarsal in his foot and he was never fully fit during the World Cup in Russia, as Brazil were knocked out in the quarter-finals by Belgium.

The Paris St Germain striker -- the most expensive player in the world following his record 222 million-euro ($231 million) switch to the French side from Barcelona in 2017 -- was also left with his reputation in tatters after being ridiculed for his haircuts, diving and tears in the tournament.

What's at stake in Qatar?

Criticised for his antics off and on the pitch in the past, fans were surprised by a seemingly different Neymar ahead of the Qatar World Cup thanks to his physical and mental preparation.

He ended his vacation a week early to begin training with PSG in the close season and is having an outstanding campaign so far. He is among the leading players for goals and assists combined in Europe's five major leagues.

Neymar can also overtake the great Pele as Brazil's all-time top scorer if he nets three more goals to add to his tally of 75 from 121 matches.

A trophy-laden club career apart, delivering Brazil's first World Cup since 2002 will go a long way in helping Neymar cement his place among the game's modern greats.