A diminutive scrapper told that he was too small to play for his country, but who eventually won a World Cup with England, a player renowned for training every day, be it Christmas or his honeymoon.
Back had retired from playing and joined the coaching staff of the famed midlands outfit by the time Cullen joined in 2005.
So the Leinster man possesses intimate knowledge of the positive effect Back can have on an Edinburgh side seeking to add graft to their craft, as they seek to build on last season's Heineken Cup semi-final run.
"Being a back-row forward, he's very sharp all around the breakdown," enthuses Cullen of his erstwhile tutor.
"The way Leicester have played and that environment he would have operated in for 20 years or so, there's such an emphasis on the set-piece, strong driving mauls. You've seen Edinburgh add that to their game.
"Neil has been around the game. He's been a head coach as well at Leeds. He's plenty of experience from a coaching and playing point of view. I've been very impressed with Edinburgh when I've seen them this season.
"There's been a definite shift in mindset from probably playing the kind of loose game they would have done in the past. They have much more structure to the way they play now and they're clearly trying to take on more teams up front as well."
Indeed, Edinburgh have already scored a couple of pushover tries this season as they seek to shake off the tag of merely being flat-track fancy dans.
Any Anglo-French conspiracy theorists aggrandising for an alteration in Heineken Cup qualification will have more fuel added to their argument by perusing the team line-ups.
Leinster are still resting Rob Kearney almost a month into the competitive season, while Michael Bradley decides to rescue his most potent back, free-scoring flying Dutchman-turned-Scot, Tim Visser, while Allan Jacobsen and Ross Rennie are also held in reserve.
Leinster have won five of the past six against Edinburgh, who have lost eight successive games against Irish opposition.
The only Scottish side to beat Leinster on their own soil since Edinburgh did so at Donnybrook in 2000 was Glasgow in September 2011.
And, despite Bradley's bravura pre-match declaration, that is a trend likely to remain unchanged by sundown this evening.
"There's a lot to build on from our first three games, having played well in a number of key areas," says Bradley.
"The difference will come in the number of chances we can create, as Leinster's defence has been the key component in their success in recent years.
"I think they will focus on that element against us because of the type of side we are, but, if we create enough chances and continue to increase our conversion rate from the last three games, then we'll be confident of winning this game."
Key indicators for Leinster ahead of their crucial trio of games next month -- Munster and their opening Heineken Cup brace of pool matches -- will be the performances of Andrew Conway and Fionn Carr on the wings.
Within a strong backline, this pair are arguably fighting it out for a squad place; Conway is marginally ahead of his rival as it stands and the absence of Visser removes a significant portion of any anxiety he might be feeling.
Carr's need is the greater, you feel.
How Tom Denton fares on his home debut will be another keenly watched aspect of the display as Leinster seek to consolidate their second-row options; South African Quinn Roux's injury is not reckoned to be serious.
Cullen may have assumed veteran status, but his message to Joe Schmidt is abundantly clear.
"I'm available for selection every week," he smiles. "I just haven't been able to get in every week.
"I got to play with Quinn against the Dragons. He's a good lump of a guy, very explosive, very dynamic. Unfortunately, he rolled his ankle, which ruled him out of last weekend.
"Tom Denton hasn't had much opportunity but he looks like a good prospect. And obviously, Damian Browne and Devin Toner have been around for a while. There's good competition for places.
"As for me, I'm 100pc fit, never been better. I haven't missed a session all year."
Verdict: Leinster to clear the handicap
Leinster -- I Nacewa; A Conway, B O'Driscoll, G D'Arcy, F Carr; J Sexton, E Reddan; C Healy, S Cronin, M Ross, L Cullen (capt), T Denton, K McLaughlin, S Jennings, J Heaslip. Reps: T Sexton, H van der Merwe, J Hagan, D Toner, J Murphy, J Cooney, I Madigan, B Macken.
Edinburgh -- G Tonks; L Jones, N De Luca, M Scott, T Brown; G Laidlaw (capt), R Rees; J Yapp, R Ford, G Cross, G Gilchrist, S Cox, S McInally, R Grant, N Talei. Reps: A Titterrell, R Hislop, W Nel, R McAlpine, D Basilaia, C Leck, H Leonard, D Fife.
Ref -- N Hennessy (WRU).
Leinster v Edinburgh,
Live, RTE 2, 6.15