England skipper John Terry concedes it is "unthinkable" his career will come to a close without tasting real success in either the Champions League with Chelsea or at international level.[LNB] Terry is preparing to lead the national team in their penultimate World Cup qualifier in Ukraine at the weekend secure in the knowledge that Fabio Capello's side are already assured of a place in South Africa next summer.[LNB] "This is my biggest season ahead of me and it's important to stay fit and keep playing well for Chelsea," Terry told the Daily Express. [LNB] "And when the England games come up, I need to show how important I am to the team and to the manager, and keep the lads moving in the right direction.[LNB] "Everybody knows the determination within myself to go on and win the Champions League with Chelsea, there is no bigger challenge than that.[LNB] "And with the England situation, I was captain of that side that didn't qualify and I took that very personally, and took a lot on my shoulders. [LNB] "I want to make sure that in my career I win the Champions League and go to the World Cup confident we can do well.[LNB] "It would 100% always annoy me if I retired without a Champions League winners' medal with Chelsea or some real success with England. [LNB] "To end my career without either of those things is unthinkable."