This article will examine Oscar's 2011 FIFA U-20 World Cup campaign, his performances in recent friendlies for Brazil, how he'll fit in at Chelsea, comments from select experts and the implications of his signing.
Oscar's hat trick against Portugal in the final allowed him to jump ahead of Michael Ortega and Clément Grenier, who were excellent midfielders but heavily reliant on dominant forwards.
Prior to the final, Oscar accumulated three assists throughout the tournament and it would've been higher if Willian  was more accurate in front of goals.
What separated Oscar from his highly rated teammate Casemiro was the Internacional midfielder's ability to pass, move, receive and provide. Casemiro could receive and provide but his movement wasn't as smooth as Oscar.
Hindsight is 20/20 but maybe Oscar could have lit up the tournament like Henrique if Ney Franco had chosen to play Oscar centrally and Coutinho in a slightly wider role.
Jonathan Wilson at ESPNSTAR.com was full of praise for Oscar:
He had been my vote for player of the tournament even before the final because of the range and intelligence of his passing and movement—and this from a player moved from his usual No. 10 role to play as a narrow left-sided midfielder. There was a strength and an uprightness to his play, a willingness to use his shoulder in the challenge despite his apparent frailty, a capacity to keep his head up, scanning his options like a footballing meerkat, that drew comparisons with Kaká.
 São Paulo's Willian not Willian from Shakhtar Donetsk.
Brazil 3-1 Denmark | Grade: A+
A majestic performance from Oscar, whose movement without possession had Christian Poulsen running rings.
Fortunate to claim an assist for Hulk's early long-range strike because Thomas Sørensen should have saved the shot. It was later revealed that Sørensen had a spinal problem—Arsenal fans will remember the Dane criticising the Gunners for lacking spine.
Four minutes after Hulk's goal, Oscar skipped past Daniel Agger, provided a lovely pass to the Porto forward only for Niki Zimling to kick the ball into his own net.
Throughout the game, Oscar was consistently involved in play whether it was moving deep to receive a simple pass from Sandro, linking up with Hulk, or providing a through-ball to his club teammate Leandro Damião.
United States 1-4 Brazil | Grade: A-
Oscar should have registered an assist after brilliantly putting Damião one-on-one against Tim Howard, but the goalkeeper made a great save—or as the Americans put it: "clutch save from Howard!"
Towards the end of the game, the US defending was diabolical (except Fabian Johnson) and Oscar was involved in various plays that could have led to goals. Mind you, the scoreline was quite harsh on the US because they played quite well in attack.
Mexico 0-2 Brazil | Grade: C
Oscar was used in a deep-lying role which was strange because he was so good as an attacking midfielder in previous friendlies for Mano Menezes. When Oscar did venture forward, he struggled against Jesús Zavala.
Argentina 4-3 Brazil | Grade: B
I cannot understand why Oscar didn't spend the majority of his time as a No. 10 when Rômulo and Sandro were holding midfielders. Either it was Oscar's decision to drop deep or another one of Menezes' bizarre tactical decisions.
Oscar combined excellently with Damião to score, which reinforced the belief that he should only play as an attacking midfielder.
Oscar and John Obi Mikel should complete 90 percent of their passes, which enables Eden Hazard more opportunities to run the show.
Ramires' direct running, which consistently troubles opposing teams (ask Pep Guardiola), gives Oscar an easy way out because the 20-year-old just needs to loft an accurate pass into space, and the Blue Kenyan will live up to his nickname.
Jordy Clasie, who has been Feyenoord's answer to Paul Scholes, would be cheaper and more reliable than Oscar as a deep-lying playmaker.
What about Frank Lampard? He played quite well as a deep-lying playmaker last season, even though it isn't his preferred position.
Oscar and Mikel are not elite ball-winners and without a consistent ball-winner in the "2" of the 4-2-3-1, Chelsea could find themselves in trouble against world-class attacking midfielders.
Three interchangeable attacking midfielders equals three playmakers and hopefully means three productive playmakers.
During the 2010-11 season, Jürgen Klopp played Mario Götze, Shinji Kagawa and Kevin Großkreutz as the "3" in the 4-2-3-1, with Nuri Şahin orchestrating from deep for Borussia Dortmund.
In Chelsea's case, Frank Lampard will play Şahin's role.
As long as the three attacking midfielders consistently interchange, it's irrelevant if they start left, right or centre.
It's not Oscar's fault but the Blues are still missing an elite ball-winner in the "2" of the 4-2-3-1. Buying a defensive midfielder has to be a priority.
There is no way that Ramires can be left out of the starting XI because he's so invaluable to Chelsea. He lacks the positional discipline to play as a deep-lying midfielder, yet the prospect of playing three interchangeable attacking midfielders is hard to pass up.
David Hytner at guardian.co.uk compiled some informative quotes about Oscar:
Mano Menezes, Brazilian national and Olympic manager, told Hytner:
He is somebody that is able to read the game and solve any problems that arise for his team. He does not rush and dribble with the ball at this feet but he finds good things to do with the ball.
Paris Saint-Germain centre-back Thiago Silva told Hytner:
The thing about Oscar is that he is a very calm guy, always with a smile on his face and never complaining about anything. He is the same on the pitch. He doesn't call much attention to himself, he is discreet but he is always very smart and intelligent.
TV Globo's Jon Cotterill told Hytner:
I've watched Oscar since his days at São Paulo and I'd describe him as the brains of the team. He has fabulous technique, good passing and vision but it's his ability to think quickly under pressure that marks him out.
South American football correspondent Tim Vickery opined on the Alan Brazil Sports Breakfast Show:
Especially given the speculation regarding Luka Modrić because that’s the kind of role you can see Oscar filling really well—the Luka Modrić role; [though] he [Oscar] is happiest a little further forward.
He is much stronger than he looks. He can get a foot in and mark but he’s a creative player for the last 40 yards of the field.
Busy, mobile, versatile, talented, brave.
If you look at most Brazilians who’ve been successful with top European clubs, they’ve tended to go to a smaller club first. Those who’ve gone straight to the likes of Real Madrid, often that hasn’t worked out too well.
The risk Oscar would be running going straight to the European champions [Chelsea], who are now in this process of reconstruction is exactly that. He might not be high enough on the totem pole to get a regular game.
Roman Abramovich is filling Chelsea to the brim with young guns. Why? He wants to build a dynasty.
Eden Hazard , Romelu Lukaku, Oscar, Josh McEachran, Lucas Piazón, Kevin De Bruyne, Oriol Romeu and Gaël Kakuta are all 21 years or younger.
If Oscar becomes a Chelsea player , it proves that Abramovich is following the old adage: sign talent over need.
Going by that proverb, Abramovich should sign Étienne Capoue and Jordy Clasie to fill the "2" of the 4-2-3-1. What about Romeu? Sell him back to Barcelona because he's so desperate to return.
 Thorgan Hazard, Eden's younger brother, will also join the Blues.