Well it was mentioned above that Rafa is C League Manager and i just stated hes won the la liga twice. Which if am right is a league. Which cant be won on penalties.
So rubbishes your comment that they need to get rid of him if they want to win league, as he has proved already in his short time managing that he can win leagues.

The mans won more than fergie did in his first few years. Easily.

Hes been to more CL Finals than Fergie has in his 20 years managing United?

So whichever way you look at hes a top manager. Which if he does leave in the summer will probably be proven by the amount of top flight teams wanting his as manager.