Shearer wrote in The Sun: "Ferguson does not just rely on new players coming in but present ones getting better.
"He trusts that Rafael can become Europe’s best full-back when others claim he is not up to it.
"He sticks with Jonny Evans while he is finding his legs, believes in Phil Jones when others suggest he is not a United player and defends David De Gea believing he might make the difference soon.
"On Wednesday in Spain much of that faith was repaid and this could be a truly historic season for this squad.
"The title is all but won, the FA Cup will not be ignored and Ferguson will drive another big performance out of his men to get past Real Madrid in a tie that is still tough to call."