The striker helped Atletico Madrid to a shock La Liga title in 2013-14 before sealing a move to Chelsea - watch our exclusive documentary here!
The striker scored an astonishing 36 goals as Diego Simeone's side stunned the world to defeat Barcelona and Real Madrid to win La Liga. They also reached the Champions League final, coming within a minute of winning an historic double before being denied by their local rivals.
Costa also made headlines by changing allegiances from the country of his birth Brazil to adopted nation Spain. The World Cup was a disappointment, with his lack of fitness playing a part as the Spaniards offered a terrible defence of their crown.
All of that handed the 25-year-old No.14 spot in this year's Goal 50 as he prepares to start the next chapter of his career with Chelsea.
Check out the video at the top of the page to watch Goal's exclusive documentary on Diego Costa, which includes contributions from Radamel Falcao, Diego Simeone and Gaizka Mendieta.
Click HERE to see the full list for the 2014 Goal 50
HAVE YOUR SAY
Do you agree with our list of the world's 50 greatest players of the 2013-14 season?
Get involved via our Goal 50 section this month. Give us all your views on the debate by commenting below and by getting in touch on Facebook or Twitter using the hashtag #Goal50.