Star of Arrow Stephen Amell was supposed to appear on WWE Backstage for Promo School. It seems that Amell pulled out due to a pinched nerve in his back. He just wasn't well enough to appear on the show but promised that a future appearance was not out of the question. Amell broke the news on Twitter.
Stephen Amell has been a longtime wrestling fan and has actually wrestled on three occasions. He wrestled once in WWE teaming up with Neville against Stardust (Cody Rhodes) and King Barrett at SummerSlam 2015. His appearance was well received.
He then wrestled at a Ring of Honor where he joined the Bullet Club faction. This actually set up his eventual match at All In against Christopher Daniels. This was actually the match that really showcased Amell's skills and proved that he could compete.
Stephen Amell is also close friends with Cody Rhodes and it's very possible that Amell will eventually appear on AEW Dynamite - it's only a matter of when and not if. Amell recently completed shooting 8 seasons of Arrow and is now in the midst of pre-production on his new show, 'Heels', which will be centered on professional wrestling.