Guus Hiddink admits dumping England out of Euro 2008 would be one of the finest moments of his career.
If Russia defeat Israel in Tel Aviv today, England's hopes of qualifying for next summer's finals in Austria and Switzerland will be all but over.
Only an unlikely string of results elsewhere would save McClaren's men should Russia record the three points and Hiddink has admitted his surprise.
Hiddink led PSV Eindhoven to the European Cup in 1988 and the Dutchman has also guided Holland and South Korea to World Cup semi-finals.
But Hiddink has revealed that helping Russia, who recorded a 2-1 win over England in Moscow last month, to qualification over McClaren's side would rate alongside those achievements as one of his finest hours.
"We're not in the finals yet, but if we get there it would be a tremendous achievement," said Hiddink.
"We are turning into a young, modern team with an average age of 23-24, playing more attractive football and it will accelerate our development hugely if we qualify.
"Halfway through the group matches I said we had to win in Macedonia, otherwise we would be playing England only for prestige.
"But I was amazed to see how well we handled the pressure and beating England in the Luzhniki was the next crucial step.
"It is good to be at the end of the qualifying campaign with two games to go and to be still in command."