It is known to many that the return of any WWE legend, for whatever period of time, has a huge impact on the WWE Universe.
But when should a professional wrestler's career become just that; one which exists purely because of brief appearances and cameos, as opposed to competitive matches?
Over the past couple of years, we have seen a whole host of past-wrestlers appear on either Monday Night Raw or SmackDown, as well as pay-per-view events such as WrestleMania.
What these WWE Superstars do during their time on air though, demonstrates the ability they have left both physically and mentally.
One of the greatest WWE wrestlers to ever exist, The Undertaker, was the subject of one of the most highly-anticipated events of WrestleMania XXX, when he faced Brock Lesnar to defend his incredible 21-0 streak.
Lesnar's win was a result which very few saw coming, but given The Phenom is now 49, perhaps it was clearer than first thought that his Streak may have been in doubt that night.
After the match, The Undertaker understandably looked battered and bruised, with many believing this to be his final match as a WWE wrestler.
This is despite the huge desire of several members of the WWE Universe to see a match up between The Undertaker and another giant name of the business, Sting.
Contrary to The Dead Man, Sting gives the impression that his age is just a number and that he cannot wait to return to the ring.
Speaking at the WWE 2K15 roster reveal event, Sting spoke of his desire to have a match against John Cena, and possibly more if his body would let him, which is questionable given that he is now 55.
The excitement and interest of WWE though, is what causes these legendary stars to want to continue to appear whenever and wherever they can as part of the company.
Hulk Hogan for example, had a special edition of Monday Night Raw take place in honour of his 61st birthday a couple of weeks ago and as far as both he and followers of WWE are concerned, this could and should be a tradition for more years to come.
The reality therefore, is that there is no real age limit for WWE. Each individual is different, and even when a person's body is telling them they are not physically able to wrestle anymore, their mind tells them a brief appearance won't hurt.