Rae, who has been influential in Aberdeen's charge to third place in the league after one round of fixtures, is massively disappointed at the penalty kicks defeat to St Mirren.
But he knows the players must put that behind them and focus on the SPL, where the Reds sit only two points behind leaders Celtic.
And the club's second-top goalscorer this term knows the team has the perfect opportunity to shake off the disappointment against Ross County this weekend.
He said: "It is devastating to miss out on the chance to go to Hampden with Aberdeen.
"I just need to get over it and concentrate on the league now. We are disappointed but we can’t let it affect our season.
"We have had a good campaign so far and we just have to keep that up."