How Derek McInnes left Michael Stewart confused after Rangers leak at Ibrox
Derek McInnes had something special up his sleeve as Rangers thrashed Celtic in the Premier Sports Cup quarter-final.
Martin O'Neill's team had no answers for the Gers at Ibrox on 13 September.
Dan Neil's brace and Kevin Kelsy's strike secured a dominant 3-0 win for the hosts in the season's first Old Firm derby.
McInnes surprised everyone with his game plan, effectively playing with a back three as James Penrice moved into the midfield.
The AEK Athens loanee played as an inverted full-back, giving the Light Blues an advantage in the engine room.
In the end, the Hoops were unable to cope with the Govan side's tactics and bowed out without putting up much of a fight.
How Michael Stewart already knew about Rangers plan vs Celtic
McInnes has received massive praise after the win against Celtic and it certainly wouldn't have been possible without him.
Michael Stewart heard a rumour before the game at Ibrox that the Scottish manager would set his team up in a 3-3-3-1 formation.
The former midfielder was left baffled and confused after the Gers' possible setup was seemingly leaked before kickoff.
McInnes made sure the Govan side had the last laugh and that's exactly why Andrew Cavenagh and 49ers Enterprises decided to appoint him as Danny Rohl's replacement.
Penrice moved into midfield to support Nicolas Raskin and Neil, with Ryan Naderi playing behind Kelsy.
Speaking on the Scottish Football Social Club on 14 September, Stewart said, "We had heard a rumour before the game that they were going with this 3-3-3-1.
"And you're thinking to yourself, 'What?' Couldn't really compute. And it worked a treat."
How Derek McInnes can perplex Martin O'Neill again with tactical tweak
O'Neill will surely take lessons from the drubbing at Ibrox and come up with a countermeasure.
McInnes may need to rethink his tactics as Rangers travel to Parkhead on 20 September.
Despite Kelsy's goal and assist, the Gers may need to drop him to the bench and bring in Badredine Bouanani to the starting lineup.
Minsu Kim didn't have the best game on the right-wing and the Algeria international could provide the quality needed on the flank.
The South Korean ace should move to the number 10 position, with Naderi starting up top as the lone striker, with the former Hansa Rostock star's industry invaluable.
McInnes can't expect to go into the upcoming fixture with the same setup and get the same result, but it remains to be seen what he decides to do at Parkhead.