Since joining the London club from Internacional in July of 2012 for a fee of £18million pounds, the Brazilian playmaker has made 95 appearances in the Premier League for the newly crowned champions, 21 of which were coming off the bench. In those appearances, Oscar has sparked Chelsea with 18 goals and and 21 assists. The Brazilian also played a role in their Capital One Cup and Premier League double this season, as well as their UEFA Europa League title back in the 2012/2013 campaign. 

He has enjoyed his shares of ups and downs during his time with the Blues, but one thing that can be said is this; he is a Mourinho-style player. The Brazilian is a tireless workhorse, which is something the Portuguese manager always looks for in his players. Go back a year to the sale of Juan Mata, whom José sold to rivals Manchester United because of his questionable defensive ability. Oscar has proven himself as a much better alternative at tracking back than Mata, who often frustrated his boss with his lack of a defensive presence. Oscar's incredible work ethic was also on display for the world to see at last year's World Cup, where the Brazilian scored a late goal in his country's embarrassing 7-1 thrashing to Germany. He played an important role as hosts finished fourth in the tournament. Alongside his work ethic, his other advantages in playing with Chelsea include: 

  1. Time: At the age of 23, he's far from the finished product. He has time on his side to learn and grow as a player. Staying at Stamford Bridge would do him well to benefit from playing alongside Cesc Fábregas, the Spaniard having proven his worth through the years.  
  2. Ability: It's evident to see that he possesses the ability to become a first-team regular at the highest level of the game. He boasts a good range of passing, smooth dribbling and a very under-rated defending ability which is under-appreciated given his technical ability. His shooting and finishing could be improved on, but with time on his side he should be able to accomplish that.
  3. National team-mates: The Blues currently have five Brazillian players on their books, four of whom including Oscar himself were on the Brazil team for the 2014 World Cup. These national team-mates that play for the same club can help to make a player feel more at home, and are a useful backbone at times as they speak the same language and make one another feel content in their surroundings. 

With a promising start to his Chelsea career at a young age, what could cause him to consider leaving the club? It's simple, opportunities, more so a lack of them. At Chelsea, Oscar will be competing with the likes of Eden Hazard, Fábregas, Willian, Juan Cuadrado and Ramires for a starting berth regularly. Depending on his form, his spot in the starting eleven is far from guaranteed. 

Mourinho's always been effective in terms of player management, and should be able to help his development. Will he leave this transfer window? Well, that remains to be seen - but with Serie A giants Juventus lurking, a possible move isn't too far away for the talented playmaker.