Sporting Lisbon are in Scotland to play Celtic and were looking for another game so offered to play Saints. However, the day they wanted to play it on was the same day that has been set aside for the cup final since mid May so it couldn't go ahead.
As Richard Littlejohn often says "You couldn't make it up." The Renfrewshire Cup is one of the most pointless football tournaments in existence, it's effectively a glorified friendly which sees us playing Morton every year with a trophy no one really cares about up for grabs (unless you support Morton). So pointless is the competition that high school teams get to the semis and Morton's semi final opponents pulled out!
So, instead of a glamour friendly against a massive European side, we have to make do with the usual rubbish like Dumbarton and Ayr United. Great.