Frankly, I'm a bit surprised that Jose Mourinho was able to convince Begovic to take a backup role at this stage of his career. The Bosnian just turned 28 years old, entering what should be the prime years of a career that is already going very well. The idea that he could be joining one of England's larger sides as their long-term starter wasn't laughable, and the links to Arsenal, Manchester United, and even Liverpool all seemed to make far more sense than those to the Blues.
Regardless, Chelsea have managed to replace the best backup keeper in the world with someone else that should certainly be in the discussion, and should Thibaut Courtois go down with injury at any point, Mourinho's side will be in very good hands. Welcome to Chelsea, Asmir.