Manchester United legend Peter Schmeichel has declared the current defence the "best in the world".
Goalkeeper Edwin van der Sar has taken a lot of credit but Schmeichel said defender Nemanja Vidic has played his part.
"Edwin gets a lot of praise but Vidic's displays in the last two years are second to none," the Dane told BBC Sport.
"We've the best defence in the world.
"I can't see anyone scoring (against them). It's great to have that feeling of confidence."