Barry Ferguson needs just one word to describe what Rangers must have to down Celtic
The Gers host their fierce rivals at Ibrox on Sunday in the quarter-finals of the Scottish League Cup.
Then, next Sunday (20 September), Derek McInnes' men will enter enemy territory in the Scottish Premiership.
It provides a unique challenge for McInnes early in his tenure at a time where his side of racked up four straight victories.
Bojan Miovski scored a last-gasp winner against St Mirren in midweek to maintain the momentum ahead of facing Martin O'Neill's side.
Former skipper and ex-interim manager Barry Ferguson knows all about the Old Firm, and he told Rangers exactly what they require for victory.
What did Barry Ferguson tell Rangers they need for the Old Firm?
It promises to be an absolute crucial week for McInnes so early in his tenure as Rangers manager.
After the Bears were embarrassingly knocked out of the Europa League and Conference League qualifying, the pressure is on to deliver domestically.
McInnes has slowly started winning the Rangers fans over, but the feelgood factor being built up will quickly be lost if the next two games don't go their way.
Ferguson is a veteran of the Old Firm derby and, writing in the Daily Record, he had just one word to describe what Rangers must have against Celtic.
He wrote: "You might think and it can be summed up in one word. Aggression."
Ferguson elaborated, adding: "Don’t get me wrong, I’m not suggesting for a minute they should set out to kick their rivals off the pitch or send people five feet up in the air.
"That’s not the kind of aggression I’m talking about. No, I’m talking about a Rangers team that sets out to knock Celtic out of their stride.
"To chase after them, press them and harass them for every ball. To force them on to the back foot from the first minute and make life so chaotic for them out there that they are struggling to catch a breath.
"Put it this way, if you’re wearing a green and white shirt inside that stadium tomorrow, you should be made to hate every single second of it."
Rangers must be at it from the off
It's do-or-die time for McInnes and Rangers already.
We might only be in September, but it is no exaggeration to suggest these next two games could define Rangers' season.
Or, at the very least, give a huge indication of how ready this new-look Rangers side is ready to compete with their rivals.
The goal, obviously, is to haul the Scottish Premiership back to Ibrox after it has presided for years at Celtic Park.
But this first fixture will be hugely importan too. Can Rangers prove a worthy challenger to Celtic domestically?
It is a huge test for McInnes so early in his time in Govan. His team must be absolutely at it from the off here.