Celtic manager Neil Lennon called for a change to the rules which saw Aberdeen reduced to 10 men when defender Andrew Considine was sent off in the first half of their 4-0 Scottish Cup semi-final defeat by the Hoops at Hampden.
The Dons had shipped 17 goals in their previous four games against Celtic this season and chances of a shock win all but went out of the window in the 18th minute when Considine was red-carded by referee William Collum for fouling Gary Hooper in the box.
Although Jamie Langfield saved Anthony Stokes' penalty, Craig Brown's side succumbed in the second half as goals from Charlie Mulgrew, Joe Ledley, Kris Commons, with a spot-kick, and substitute Shaun Maloney set up a meeting with Motherwell in the May 21 final.
The Celtic boss accepted that Considine's dismissal had handed his side a huge advantage.
"Psychologically for Aberdeen it was damaging," said Lennon. "But I do think it was a penalty and in the interpretation of the laws of the game, the referee probably had no choice but to send him off.
"I think it is one rule that could be doing with being looked at."