Brock Lesnar has time and again defied his age in WWE, but it eventually catches up to every wrestler. The most recent example of this occurred last Friday when The Beast Incarnate nearly injured himself.The former Universal Champion has been embroiled in a feud with John Cena since coming back at SummerSlam this year. The two will face each other for the final time at WWE Wrestlepalooza on September 20.Lesnar has been on a warpath, and he made his intentions clear when he returned to SmackDown in Chicago last week to attack John Cena. He did so during the United States Championship match between Cena and Sami Zayn (c).The Beast dragged the referee, Dan Engler, out of the ring before entering it. Now, unseen footage of Lesnar seemingly tweaking his ankle just as he entered the ring has surfaced online.You can check out the viral clip below.Fortunately, Brock Lesnar avoided what could have been a serious injury just days before his highly anticipated showdown with John Cena. The Beast Incarnate was able to hit Zayn and Cena with F5s.Brock Lesnar's next WWE appearance announcedWith John Cena capping off his SmackDown run, Brock Lesnar is expected to continue the storyline on the blue brand.Michael Cole announced that The Beast Incarnate will make his presence felt on the September 12 edition of WWE SmackDown, which will take place in Norfolk, VA. There's no word on what he will be doing on the show.As for The Franchise Player, he is advertised to appear on the September 15 episode of Monday Night RAW. John Cena has only seven dates left in his farewell tour, which will come to an end at Saturday Night's Main Event on December 13. Will he be able to overcome The Beast Incarnate? Only time will tell.