Stephen Amell made an appearance at the Wizard World Chicago to dish some pretty interesting spoilers for "Arrow" season 4, including the possible visit of Batman to the city.

According to the actor, per Comic Book Movie, he has talked with DC Entertainment boss Diane Nelson about the possibility of the Dark Knight coming to "Arrow."

But Stephen Amell said that it's hard to get the hopes up because bringing in Batman to "Arrow" would be difficult. Apparently, the DC exec told him that the intention has always been to create "the best version of each thing and not forcing crossovers just for the sake of forcing them."

"In the same way that... [Ezra Miller's] playing the Flash in the cinematic universe -- theoretically, we haven't seen him yet," he said. "I see no reason why we couldn't have our own Bruce Wayne. That's my opinion; that might not be DC's opinion, and they're the bosses."

But the actor did say that he already filmed scenes with "Constantine" actor Matt Ryan, who will make an appearance as the occult expert on "Arrow" season 4.

"He is such a treat," Stephen Amell said of Matt Ryan. "And a trip. He's always saying his lines -- and he's getting ready to go on Broadway right now with Kiera Knightley, so he's always saying those lines, too."

While Batman heading to Starling City might not set in stone, what's sure is Charlotte Ross coming back for "Arrow" season 4.

TVLine dished more spoilers as it reported that the actress will reprise her role as Donna, Felicity's mom.

The article said, "Of course, the last time we saw Donna she had nudged her daughter to follow her heart in the direction of one Oliver Queen - who, Felicity lamented at the time, was 'terminally unavailable.' But things sure have changed since then, haven't they?"

Watch out for more "Arrow" season 4 spoilers which will be published as they come along.