The Liverpool fans managed to prank the United players in training at the WACA in Perth, by releasing an airplane with a banner showing "Liverpool FC - 6 X European Champions" that did a fly past while the players trained below.
It was timed to absolute perfection, and highlighted just how big the rivalry is, even outside the United Kingdom.
Liverpool won their sixth Champions League title last season, ensuring they have now doubled Manchester United's tally.
No doubt it was an untimely reminder for Solskjaer and Co, although perhaps it motivated them to push harder in their pre-season session.
But an hour before United's open training session at the WACA Ground, a plane was spotted in the sky.
A section of the Liverpool fans have chose to rub it into their league rivals as part of the banter between the two clubs. That said, Klopp's side's triumph over Tottenham in Madrid put them three European Cup wins ahead of United, who have claimed three in their history.
Manchester United will take on Perth Glory on Saturday night, before facing off against Leeds four days later.
'Sometimes when go away you get new enthusiasm, energy and coming here, yes we know it's a long way to go, but that's part of being at Man Utd.
"I think the players have done well".
'I'm used to it, I played here for 11 years, I'm used to that pre-season.