The rivalry between Sir Alex Ferguson and Arsene Wenger is the stuff of Premier League legend.

At the helms of Manchester United and Arsenal, the pair of veteran tinker-men oversaw the development of two of the finest teams the English top flight has ever seen and, every so often, those two fantastic teams played each other.

While, for the most part, all eyes were on the glut of stars on the pitch, there were times when attentions couldn't help but turn to the two men on the sidelines.

There really was no love lost between the pair, so much so that it was incredibly rare for them to share a drink post-game, as is the tradition in English football.

So you can imagine that, after a 1-1 draw and years of bitter back and forth, that it came as a massive surprise to see Ferguson at the door to Wenger's office at the Emirates in 2008.

For the gathered staff, something felt amiss but Ferguson was there for a very specific purpose as highlighted by Wenger's right-hand man Dick Law in report in The Mirror.

“The rivalry between the two of them was intense and unforgiving. At times, the bitterness of a specific result would spill over. In short, there was little love lost between the two," Law said.

“Sir Alex Ferguson’s appearance in the Manager’s Office that day was unusual. Over the years, I could count on one hand, with a few fingers to spare, the number of times that Sir Alex had made the trek from the visitor’s dressing room to the Manager’s Office.

“The Manager’s Office that day was set up with two easy chairs against one wall, a coffee table with a sofa on one side and some other chairs on the other.

“Sir Alex graciously greeted the Arsenal coaching staff and before I realised it, he and Arsène went over and sat in the easy chairs. Everyone kept their distance. The moment was unique.

“Long-time rivals, seated together, leaning towards each other, talking. What we saw in the Manager’s Office wasn’t a post-match courtesy call, it was good-bye.

“Ten days later, the 8th of May, Sir Alex resigned as Manager of Manchester United.”

Superb.

While they may not have had much time for each other, you can be certain that, away from the limelight and the fierce media attention, there was a deep lying mutual respect between the pair.

Ferguson taking the time to go and see Wenger after one of his last clashes with his eternal rival only underpins that.