Not too long ago, NBC cancelled "Constantine," a Vertigo (DC Comics imprint) adaptation of the foul-mouthed occult detective and sorcerer with a gritty attitude just after its freshman run. The cast and the crew as well as the fans that fell in love with it petitioned to save the show but were unsuccessful.

In the midst of the shocking cancellation issue, "Arrow" star Stephen Amell had an idea: a crossover of the worlds. The actor tweeted that whichever network or streaming site revives the series, he will guest star as Oliver Queen. Sadly, even with such attractive offer, "Constantine" remained dead.

#SaveConstantine -- Hey TV Networks / Netflix and the like... If you pick up the show, I'll guest star.

— Stephen Amell (@amellywood) May 9, 2015

But this might just change in "Arrow" season 4. During the San Diego Comic-Con, Amell, Emily Bett Rickards aka Felicity Smoak and executive producer Wendy Mericle sat down for a chat with IGN and talked about this possibility. As it turns out, the efforts to bring Constantine back are still ongoing.

When asked about having the chain-smoking anti-hero in "Arrow" season 4 or any of its future seasons, Mericle replied "Yeah, we really want to do it. It's something we've been talking to DC about and it's just a question of some political things, but also the actor's schedule."

Mericle was careful not to make any promises though and simply concluded that "We're trying to work it out, but we don't know 100 percent if it's going to happen. But we're really optimistic and we would love to have him," with Amell adding "Fingers crossed."

Den of Geek thinks that this guest-starring role for Matt Ryan, who essayed the character, is better than not having a dose of the actor mustering as much cynicism required to become John Constantine. In fact, with this as a must-do for Marc Guggenheim, Mericle and even Amell, this may actually happen.

To note, Ryan has also expressed the interest of gracing Starling City, tweeting Amell back after his petition that "it would be a real pleasure to explore these guys dynamic." With this, Mericle and the team won't a hard time swaying the actor.

@amellywood man, it would be a real pleasure to explore these Guys dynamic #Constantine #SaveConstantine — Matt Ryan (@mattryanreal) May 9, 2015

Should "Constantine" join this fold, only time will tell. "Arrow" season 4 premieres October 7.